< draft-ietf-alto-path-vector-06.txt   draft-ietf-alto-path-vector-07.txt >
ALTO WG K. Gao ALTO WG K. Gao
Internet-Draft Tsinghua University Internet-Draft Sichuan University
Intended status: Standards Track Y. Lee Intended status: Standards Track Y. Lee
Expires: December 20, 2019 Huawei Expires: January 9, 2020 Huawei
S. Randriamasy S. Randriamasy
Nokia Bell Labs Nokia Bell Labs
Y. Yang Y. Yang
Yale University Yale University
J. Zhang J. Zhang
Tongji University Tongji University
June 18, 2019 July 8, 2019
ALTO Extension: Path Vector Cost Type ALTO Extension: Path Vector Cost Type
draft-ietf-alto-path-vector-06 draft-ietf-alto-path-vector-07
Abstract Abstract
The Application-Layer Traffic Optimization (ALTO) protocol [RFC7285] The Application-Layer Traffic Optimization (ALTO) protocol [RFC7285]
has defined cost maps and endpoint cost maps to provide basic network has defined cost maps and endpoint cost maps to provide basic network
information. However, they provide only scalar (numerical or information. However, they provide only scalar (numerical or
ordinal) cost mode values, which are insufficient to satisfy the ordinal) cost mode values, which are insufficient to satisfy the
demands of solving more complex network optimization problems. This demands of solving more complex network optimization problems. This
document introduces an extension to the base ALTO protocol, namely document introduces an extension to the base ALTO protocol, namely
the path-vector extension, which allows ALTO clients to query the path-vector extension, which allows ALTO clients to query
skipping to change at page 2, line 7 skipping to change at page 2, line 7
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 20, 2019. This Internet-Draft will expire on January 9, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Use Case: Capacity Region for Co-Flow Scheduling . . . . . . 5 3. Use Case . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Overview of Path Vector Extensions . . . . . . . . . . . . . 7 3.1. Capacity Region for Co-Flow Scheduling . . . . . . . . . 5
4.1. New Cost Mode to Encode Path Vectors . . . . . . . . . . 7 3.2. In-Network Caching . . . . . . . . . . . . . . . . . . . 7
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. New Cost Mode to Encode Path Vectors . . . . . . . . . . 8
4.2. New ALTO Entity Domain for ANE Properties . . . . . . . . 8 4.2. New ALTO Entity Domain for ANE Properties . . . . . . . . 8
4.3. Multipart/Related Resource for Consistency . . . . . . . 8 4.3. Multipart/Related Resource for Consistency . . . . . . . 9
5. Path-Vector Cost Type . . . . . . . . . . . . . . . . . . . . 9 5. Basic Data Types . . . . . . . . . . . . . . . . . . . . . . 10
5.1. Cost Mode: path-vector . . . . . . . . . . . . . . . . . 10 5.1. ANE Identifier . . . . . . . . . . . . . . . . . . . . . 10
5.2. Cost Metric: Link Maximum Reservable Bandwidth . . . . . 10 5.2. Path Vector Cost Type . . . . . . . . . . . . . . . . . . 10
6. ANE Domain . . . . . . . . . . . . . . . . . . . . . . . . . 10 5.2.1. Cost Metric: ane-path . . . . . . . . . . . . . . . . 11
6.1. Domain Name . . . . . . . . . . . . . . . . . . . . . . . 11 5.2.2. Cost Mode: array . . . . . . . . . . . . . . . . . . 11
6.2. Domain-Specific Entity Identifier . . . . . . . . . . . . 11 5.3. ANE Domain . . . . . . . . . . . . . . . . . . . . . . . 11
6.3. Hierarchy and Inheritance . . . . . . . . . . . . . . . . 11 5.3.1. Domain Name . . . . . . . . . . . . . . . . . . . . . 11
7. Multipart Filtered Cost Map for Path Vector . . . . . . . . . 11 5.3.2. Domain-Specific Entity Identifier . . . . . . . . . . 11
7.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 11 5.3.3. Hierarchy and Inheritance . . . . . . . . . . . . . . 11
7.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . . . 11 5.4. ANE Properties . . . . . . . . . . . . . . . . . . . . . 11
7.3. Accept Input Parameters . . . . . . . . . . . . . . . . . 12 5.4.1. ANE Property: Maximum Reservable Bandwidth . . . . . 11
7.4. Capabilities . . . . . . . . . . . . . . . . . . . . . . 12 5.4.2. ANE Property: Persistent Entity . . . . . . . . . . . 12
7.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6. Service Extensions . . . . . . . . . . . . . . . . . . . . . 12
7.6. Response . . . . . . . . . . . . . . . . . . . . . . . . 12 6.1. Multipart Filtered Cost Map for Path Vector . . . . . . . 12
8. Multipart Endpoint Cost Service for Path Vector . . . . . . . 13 6.1.1. Media Type . . . . . . . . . . . . . . . . . . . . . 12
8.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 13 6.1.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . 12
8.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . . . 13 6.1.3. Accept Input Parameters . . . . . . . . . . . . . . . 12
8.3. Accept Input Parameters . . . . . . . . . . . . . . . . . 13 6.1.4. Capabilities . . . . . . . . . . . . . . . . . . . . 13
8.4. Capabilities . . . . . . . . . . . . . . . . . . . . . . 13 6.1.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . 13
8.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.1.6. Response . . . . . . . . . . . . . . . . . . . . . . 13
8.6. Response . . . . . . . . . . . . . . . . . . . . . . . . 14 6.2. Multipart Endpoint Cost Service for Path Vector . . . . . 15
9. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.2.1. Media Type . . . . . . . . . . . . . . . . . . . . . 15
9.1. Information Resource Directory Example . . . . . . . . . 14 6.2.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . 15
9.2. Example #1 . . . . . . . . . . . . . . . . . . . . . . . 16 6.2.3. Accept Input Parameters . . . . . . . . . . . . . . . 15
9.3. Example #2 . . . . . . . . . . . . . . . . . . . . . . . 17 6.2.4. Capabilities . . . . . . . . . . . . . . . . . . . . 15
9.4. Example for Incremental Update . . . . . . . . . . . . . 19 6.2.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . 15
10. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 20 6.2.6. Response . . . . . . . . . . . . . . . . . . . . . . 16
10.1. Compatibility with Base ALTO Clients/Servers . . . . . . 20 7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.2. Compatibility with Multi-Cost Extension . . . . . . . . 21 7.1. Information Resource Directory Example . . . . . . . . . 17
10.3. Compatibility with Incremental Update . . . . . . . . . 21 7.2. Example: Multipart Filtered Cost Map . . . . . . . . . . 19
11. General Discussions . . . . . . . . . . . . . . . . . . . . . 21 7.3. Example: Multipart Endpoint Cost Service . . . . . . . . 20
11.1. Provide Calendar for Property Map . . . . . . . . . . . 21 7.4. Example: Incremental Updates . . . . . . . . . . . . . . 22
11.2. Constraint Tests for General Cost Types . . . . . . . . 22 8. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . 24
11.3. General Multipart Resources Query . . . . . . . . . . . 22 8.1. Compatibility with Base ALTO Clients/Servers . . . . . . 24
12. Security Considerations . . . . . . . . . . . . . . . . . . . 22 8.2. Compatibility with Multi-Cost Extension . . . . . . . . . 24
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 8.3. Compatibility with Incremental Update . . . . . . . . . . 24
13.1. ALTO Cost Mode Registry . . . . . . . . . . . . . . . . 23 9. General Discussions . . . . . . . . . . . . . . . . . . . . . 25
13.2. ALTO Entity Domain Registry . . . . . . . . . . . . . . 23 9.1. Provide Calendar for Property Map . . . . . . . . . . . . 25
13.3. ALTO Property Type Registry . . . . . . . . . . . . . . 24 9.2. Constraint Tests for General Cost Types . . . . . . . . . 25
14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24 9.3. General Multipart Resources Query . . . . . . . . . . . . 25
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 10. Security Considerations . . . . . . . . . . . . . . . . . . . 26
15.1. Normative References . . . . . . . . . . . . . . . . . . 24 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
15.2. Informative References . . . . . . . . . . . . . . . . . 25 11.1. ALTO Cost Mode Registry . . . . . . . . . . . . . . . . 27
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 11.2. ALTO Entity Domain Registry . . . . . . . . . . . . . . 27
11.3. ALTO Property Type Registry . . . . . . . . . . . . . . 27
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
13.1. Normative References . . . . . . . . . . . . . . . . . . 28
13.2. Informative References . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29
1. Introduction 1. Introduction
The base ALTO protocol [RFC7285] is designed to expose network The base ALTO protocol [RFC7285] is designed to expose network
information through services such as cost maps and endpoint cost information through services such as cost maps and endpoint cost
service. These services use an extreme "single-node" network service. These services use an extreme "single-node" network
abstraction, which represents a whole network as a single node, and abstraction, which represents a whole network as a single node, and
hosts as "endpoint groups" directly connected to the node. hosts as "endpoint groups" directly connected to the node.
Although the "single-node" abstraction works well in many settings, Although the "single-node" abstraction works well in many settings,
skipping to change at page 4, line 46 skipping to change at page 5, line 5
This document proposes the path vector extension to the ALTO protocol This document proposes the path vector extension to the ALTO protocol
to satisfy these additional requirements . to satisfy these additional requirements .
Specifically, the extension encodes the array (AR-1) of ANEs over an Specifically, the extension encodes the array (AR-1) of ANEs over an
end-to-end path using a new cost type, and conveys the properties of end-to-end path using a new cost type, and conveys the properties of
ANEs (AR-2) using unified property map ANEs (AR-2) using unified property map
[I-D.ietf-alto-unified-props-new]. The path vector and ANE [I-D.ietf-alto-unified-props-new]. The path vector and ANE
properties are conveyed in a single message encoded as a multipart/ properties are conveyed in a single message encoded as a multipart/
related message to satisfy AR-3. related message to satisfy AR-3.
The rest of this document is organized as follows. Section 3 gives The rest of this document is organized as follows. Section 3.1 gives
an example of co-flow scheduling and illustrates the limitations of an example of co-flow scheduling and illustrates the limitations of
the base ALTO protocol in such a use case. Section 4 gives an the base ALTO protocol in such a use case. Section 4 gives an
overview of the path vector extension. Section 5 introduces a new overview of the path vector extension. Section 5.2 introduces a new
cost type. Section 6 registers a new domain in Domain Registry. cost type. Section 5.3 registers a new domain in Domain Registry.
Section 7 and Section 8 define new ALTO resources to support Path Section 6.1 and Section 6.2 define new ALTO resources to support Path
Vector query by using the request format of Filtered Cost Map and Vector query by using the request format of Filtered Cost Map and
Endpoint Cost Service. Section 9 presents several examples. Endpoint Cost Service. Section 7 presents several examples.
Section 10 and Section 11 discusses compatibility issues with other Section 8 and Section 9 discusses compatibility issues with other
existing ALTO extensions and design decisions. Section 12 and existing ALTO extensions and design decisions. Section 10 and
Section 13 review the security and IANA considerations. Section 11 review the security and IANA considerations.
2. Terminology 2. Terminology
Besides the terms defined in [RFC7285] and Besides the terms defined in [RFC7285] and
[I-D.ietf-alto-unified-props-new], this document also uses the [I-D.ietf-alto-unified-props-new], this document also uses the
following additional terms: Abstract Network Element and Path Vector. following additional terms: Abstract Network Element and Path Vector.
o Abstract Network Element (ANE): An abstract network element is an o Abstract Network Element (ANE): An abstract network element is an
abstraction of network components. It can be an aggregation of abstraction of network components. It can be an aggregation of
links, middleboxes, virtualized network function (VNF), etc. An links, middleboxes, virtualized network function (VNF), etc. An
abstract network element has two types of attributes: a name and a abstract network element has two types of attributes: a name and a
set of properties. set of properties.
o Path Vector: A path vector is an array of ANEs. It presents an o Path Vector: A path vector is an array of ANEs. It presents an
abstract network path between source/destination points such as abstract network path between source/destination points such as
PIDs or endpoints. PIDs or endpoints.
3. Use Case: Capacity Region for Co-Flow Scheduling 3. Use Case
3.1. Capacity Region for Co-Flow Scheduling
Assume that an application has control over a set of flows, which may Assume that an application has control over a set of flows, which may
go through shared links or switches and share a bottleneck. The go through shared links or switches and share a bottleneck. The
application hopes to schedule the traffic among multiple flows to get application hopes to schedule the traffic among multiple flows to get
better performance. The capacity region information for those flows better performance. The capacity region information for those flows
will benefit the scheduling. However, existing cost maps cannot will benefit the scheduling. However, existing cost maps cannot
reveal such information. reveal such information.
Specifically, consider a network as shown in Figure 1. The network Specifically, consider a network as shown in Figure 1. The network
has 7 switches (sw1 to sw7) forming a dumb-bell topology. Switches has 7 switches (sw1 to sw7) forming a dumb-bell topology. Switches
skipping to change at page 6, line 42 skipping to change at page 6, line 42
+------+ +------+ +------+ +------+
| | | |
+----------------------+ +----------------------+
Figure 2: Base Single-Node Topology Abstraction. Figure 2: Base Single-Node Topology Abstraction.
Consider an application overlay (e.g., a large data analysis system) Consider an application overlay (e.g., a large data analysis system)
which wants to schedule the traffic among a set of end host source- which wants to schedule the traffic among a set of end host source-
destination pairs, say eh1 -> eh2 and eh3 -> eh4. The application destination pairs, say eh1 -> eh2 and eh3 -> eh4. The application
can request a cost map providing end-to-end available bandwidth, can request a cost map providing end-to-end available bandwidth,
using "availbw" as cost-metric and "numerical" as cost-mode. using 'availbw' as cost-metric and 'numerical' as cost-mode.
The application will receive from ALTO server that the bandwidth of The application will receive from ALTO server that the bandwidth of
eh1 -> eh2 and eh3 -> eh4 are both 100 Mbps. But this information is eh1 -> eh2 and eh3 -> eh4 are both 100 Mbps. But this information is
not enough. Consider the following two cases: not enough. Consider the following two cases:
o Case 1: If eh1 -> eh2 uses the path eh1 -> sw1 -> sw5 -> sw6 -> o Case 1: If eh1 -> eh2 uses the path eh1 -> sw1 -> sw5 -> sw6 ->
sw7 -> sw2 -> eh2 and eh3 -> eh4 uses path eh3 -> sw3 -> sw5 -> sw7 -> sw2 -> eh2 and eh3 -> eh4 uses path eh3 -> sw3 -> sw5 ->
sw7 -> sw4 -> eh4, then the application will obtain 200 Mbps. sw7 -> sw4 -> eh4, then the application will obtain 200 Mbps.
o Case 2: If eh1 -> eh2 uses the path eh1 -> sw1 -> sw5 -> sw7 -> o Case 2: If eh1 -> eh2 uses the path eh1 -> sw1 -> sw5 -> sw7 ->
skipping to change at page 7, line 26 skipping to change at page 7, line 26
o The network needs to provide the necessary abstraction to hide the o The network needs to provide the necessary abstraction to hide the
real topology information while providing enough information to real topology information while providing enough information to
applications. applications.
The path vector extension defined in this document provides a The path vector extension defined in this document provides a
solution to address the preceding issue. solution to address the preceding issue.
See [I-D.bernstein-alto-topo] for a more comprehensive survey of use See [I-D.bernstein-alto-topo] for a more comprehensive survey of use
cases where extended network topology information is needed. cases where extended network topology information is needed.
4. Overview of Path Vector Extensions 3.2. In-Network Caching
Consider a network as shown in Figure 3. Two clients (C1/eh2 and C2/
eh3) are downloading data from a server (S/eh1) and the network
provides an HTTP proxy which can cache results. The clients and the
server are controlled by an ALTO client.
+---------+
| Caching |
-+ Proxy |
/ | |
S +-------+ / +---------+
eh1__| sub |_ /
| net 1 | \ +--|---+ +----------+
+-------+ ---| | | | C2
| Gate +---------+ Internet |__eh3
C1 +-------+ --| way | | |
eh2__| sub |__/ +------+ +----------+
| net 2 |
+-------+
Figure 3: Raw Topology for the In-Network Caching Use Case.
Without the traffic correlation information, the ALTO client cannot
know whether or how the traffic goes through the proxy. For example,
if subnet1 and subnet2 are directly connected and the traffic from
eh1 to eh2 bypasses the gateway, the in-network cache can only be
used for traffic from C2 to S and is less effective.
4. Overview
This section presents an overview of approaches adopted by the path This section presents an overview of approaches adopted by the path
vector extension. It assumes that the readers are familiar with cost vector extension. It assumes that the readers are familiar with cost
map and endpoint cost service defined in [RFC7285]. The path vector map and endpoint cost service defined in [RFC7285]. The path vector
extension also requires the support of Filtered Property Map defined extension also requires the support of Filtered Property Map defined
in [I-D.ietf-alto-unified-props-new]. in [I-D.ietf-alto-unified-props-new].
The path vector extension is composed of three building blocks: (1) a The path vector extension is composed of three building blocks: (1) a
new cost mode to encode path vectors in a cost map or an endpoint new cost mode to encode path vectors in a cost map or an endpoint
cost map; (2) a new ALTO entity domain to enable ANE property cost map; (2) a new ALTO entity domain to enable ANE property
skipping to change at page 7, line 52 skipping to change at page 8, line 33
4.1. New Cost Mode to Encode Path Vectors 4.1. New Cost Mode to Encode Path Vectors
Existing cost modes defined in [RFC7285] allow only scalar cost Existing cost modes defined in [RFC7285] allow only scalar cost
values. However, the "path vector" abstraction requires to convey values. However, the "path vector" abstraction requires to convey
vector format information (AR-1). To fulfill this requirement, this vector format information (AR-1). To fulfill this requirement, this
document defines a new "cost-mode" named path vector to indicate that document defines a new "cost-mode" named path vector to indicate that
the cost value is an array of ANEs. A path vector abstraction should the cost value is an array of ANEs. A path vector abstraction should
be computed for a specific performance metric, and this is achieved be computed for a specific performance metric, and this is achieved
using the existing "cost-metric" component of cost type. The details using the existing "cost-metric" component of cost type. The details
of the new "cost-mode" is given in Section 5. of the new "cost-mode" is given in Section 5.2.
4.2. New ALTO Entity Domain for ANE Properties 4.2. New ALTO Entity Domain for ANE Properties
A path vector of ANEs contains only the abstracted routing elements A path vector of ANEs contains only the abstracted routing elements
between a source and a destination. Hence, an application can find between a source and a destination. Hence, an application can find
shared ANEs of different source-destination pairs but cannot know the shared ANEs of different source-destination pairs but cannot know the
shared ANEs' properties. For the capacity region use case in shared ANEs' properties. For the capacity region use case in
Section 3, knowing that eh1->eh2 and eh3->eh4 share ANEs but not the Section 3.1, knowing that eh1->eh2 and eh3->eh4 share ANEs but not
available bandwidth of the shared ANEs, is not enough. the available bandwidth of the shared ANEs, is not enough.
To encode ANE properties like the available bandwidth in a path To encode ANE properties like the available bandwidth in a path
vector query response, this document uses the unified property vector query response, this document uses the unified property
extension defined in [I-D.ietf-alto-unified-props-new]. extension defined in [I-D.ietf-alto-unified-props-new].
Specifically, for each path vector query, the ALTO server generates a Specifically, for each path vector query, the ALTO server generates a
property map associated to the (endpoint) cost map as follows: property map associated to the (endpoint) cost map as follows:
o a dynamic entity domain of an entity domain type "ane" is o a dynamic entity domain of an entity domain type "ane" is
generated to contain the generated ANEs. Each ANE has the same generated to contain the generated ANEs. Each ANE has the same
unique identifier in the path vectors and in the dynamic entity unique identifier in the path vectors and in the dynamic entity
domain; domain;
o each entity in this dynamic entity domain has the property defined o each entity in this dynamic entity domain has the properties
by the "cost-metric" that generated the ANEs in the query. specified by the client.
Detailed information and specifications are given in Section 6. Detailed information and specifications are given in Section 5.3.
4.3. Multipart/Related Resource for Consistency 4.3. Multipart/Related Resource for Consistency
Path vectors and the property map containing the ANEs are two Path vectors and the property map containing the ANEs are two
different types of objects, but they require strong consistency. One different types of objects, but they require strong consistency. One
approach to achieving strong consistency is to define a new media approach to achieving strong consistency is to define a new media
type to contain both objects, but this violates modular design. type to contain both objects, but this violates modular design.
Another approach is to provide the objects in two different Another approach is to provide the objects in two different
information resources. Thus, an ALTO client needs to make separate information resources. Thus, an ALTO client needs to make separate
skipping to change at page 9, line 46 skipping to change at page 10, line 29
part separately using the "Resource-Id" header. part separately using the "Resource-Id" header.
By applying the design above, for each path vector query, an ALTO By applying the design above, for each path vector query, an ALTO
server returns the path vectors and the associated property map server returns the path vectors and the associated property map
modularly and consistently. An ALTO server can reuse the data models modularly and consistently. An ALTO server can reuse the data models
of the existing information resources. And an ALTO client can of the existing information resources. And an ALTO client can
subscribe to the incremental updates for the dynamic generated subscribe to the incremental updates for the dynamic generated
information resources without any changes, if th ALTO server provides information resources without any changes, if th ALTO server provides
incremental updates for them. incremental updates for them.
5. Path-Vector Cost Type 5. Basic Data Types
This document extends the cost types defined in Section 6.1 of 5.1. ANE Identifier
[RFC7285] by introducing a new cost mode "path-vector". In the rest
of the document, we use "path-vector" to indicate the cost type with
the cost-mode "path-vector" for short.
5.1. Cost Mode: path-vector An ANE identifier is encoded as a JSON string. The string MUST be no
more than 64 characters, and it MUST NOT contain characters other
than US-ASCII alphanumeric characters (U+0030-U+0039, U+0041-U+005A,
and U+0061-U+007A), the hyphen ("-", U+002D), the colon (":",
U+003A), the at sign ("@", code point U+0040), the low line ("_",
U+005F), or the "." separator (U+002E). The "." separator is
reserved for future use and MUST NOT be used unless specifically
indicated in this document, or an extension document.
This document extends the CostMode defined in Section 10.5 of The type ANEIdentifier is used in this document to indicate a string
[RFC7285] with a new cost mode: "path-vector". This cost mode of this format.
indicates that every cost value in a cost map represents an array of
ANEs which are defined in Section 6.2, rather than a JSON number or a
ranking order.
The ANEs computed by the ALTO server associate to the cost metric for 5.2. Path Vector Cost Type
the "path-vector" cost mode. This document re-defines some cost
metrics for "path-vector", which are motivated by the co-flow
scheduling use case. The ALTO client SHOULD ignore the "path-vector"
cost mode with any other cost metrics, unless the future documents
define other cost metrics or specify the semantics of existing cost
metrics for "path-vector" cost mode for some additional requirements.
5.2. Cost Metric: Link Maximum Reservable Bandwidth This document defines a new cost type, which is referred to as the
"path vector" cost type. An ALTO server MUST offer this cost type if
it supports the path vector extension.
This document uses the same metric name, units of measurement and 5.2.1. Cost Metric: ane-path
measurement point(s) with potential measurement domain defined by
section 4.1 of [I-D.ietf-alto-performance-metrics], but specifies
different metric description and method of measurement or calculation
for "path-vector" cost mode only.
Metric Description: When used with "path-vector" cost mode, it is to This cost metric conveys an array of ANE identifiers, where each
specify the path vector computed by using the spatial and temporal identifier uniquely represents an ANE traversed by traffic from a
maximum reservable bandwidth over each network link. The value of source to a destination.
the maximum reservable bandwidth of each ANE in the path vector is
specified in the associated property map.
Method of Measurement or Calculation: The value of Maximum 5.2.2. Cost Mode: array
Reservable Bandwidth is the bandwidth measured between two
directly connected IS-IS neighbors, OSPF neighbors or BGP
neighbors. The associated ANEs are computed by some algorithm
which can guarantee the equivalent Maximum Reservable Bandwidth
constraints.
6. ANE Domain This cost mode indicates that every cost value in a cost map or an
endpoint cost map MUST be interpreted as a JSON array object.
Note that this cost mode only requires the cost value to be a JSON
array of JSONValue. However, an ALTO server that enables this
extension MUST return a JSON array of ANEIdentifier (Section 5.1)
when the cost metric is "ane-path".
5.3. ANE Domain
This document specifies a new ALTO entity domain called "ane" in This document specifies a new ALTO entity domain called "ane" in
addition to the ones in [I-D.ietf-alto-unified-props-new]. The ANE addition to the ones in [I-D.ietf-alto-unified-props-new]. The ANE
domain associates property values with the ANEs in a network. The domain associates property values with the ANEs in a network. The
entity in ANE domain is often used in the path vector by cost maps or entity in ANE domain is often used in the path vector by cost maps or
endpoint cost resources. Accordingly, the ANE domain always depends endpoint cost resources. Accordingly, the ANE domain always depends
on a cost map or an endpoint cost map. on a cost map or an endpoint cost map.
6.1. Domain Name 5.3.1. Domain Name
ane ane
6.2. Domain-Specific Entity Identifier 5.3.2. Domain-Specific Entity Identifier
The entity identifier of ane domain is encoded as a JSON string. The
string MUST be no more than 64 characters, and it MUST NOT contain
characters other than US-ASCII alphanumeric characters
(U+0030-U+0039, U+0041-U+005A, and U+0061-U+007A), the hyphen ("-",
U+002D), the colon (":", U+003A), the at sign ("@", code point
U+0040), the low line ("_", U+005F), or the "." separator (U+002E).
The "." separator is reserved for future use and MUST NOT be used
unless specifically indicated in this document, or an extension
document.
To simplify the description, we use "ANE name" to indicate the
identifier of an entity in ANE domain in this document.
The ANE name is usually unrelated to the physical device information. The entity identifier of ANE domain uses the same encoding as
It is usually generated by the ALTO server on demand and used to ANEIdentifier (Section 5.1).
distinguish from other ANEs in its dependent cost map or endpoint
cost map.
6.3. Hierarchy and Inheritance 5.3.3. Hierarchy and Inheritance
There is no hierarchy or inheritance for properties associated with There is no hierarchy or inheritance for properties associated with
ANEs. ANEs.
7. Multipart Filtered Cost Map for Path Vector 5.4. ANE Properties
5.4.1. ANE Property: Maximum Reservable Bandwidth
The maximum reservable bandwidth property conveys the maximum
bandwidth that can be reserved for traffic from a source to a
destination and is indicated by the property name "maxresbw". The
value MUST be encoded as a numerical cost value as defined in
Section 6.1.2.1 of [RFC7285] and the unit is bit per second.
If this property is requested but is missing for a given ANE, it MUST
be interpreted as that the ANE does not support bandwidth reservation
but have sufficiently large bandwidth for all traffic that traverses
it.
5.4.2. ANE Property: Persistent Entity
The persistent entity property conveys the physical or logical
network entities (e.g., links, in-network caching service) that are
contained by an abstract network element. It is indicated by the
property name "persistent-entity". The value is encoded as a JSON
array of entity identifiers ([I-D.ietf-alto-unified-props-new]).
These entity identifiers are persistent so that a client CAN further
query their properties for future use.
If this property is requested but is missing for a given ANE, it MUST
be interpreted as that no such entities exist in this ANE.
6. Service Extensions
6.1. Multipart Filtered Cost Map for Path Vector
This document introduces a new ALTO resource called Multipart This document introduces a new ALTO resource called Multipart
Filtered Cost Map resource, which allows an ALTO server to provide Filtered Cost Map resource, which allows an ALTO server to provide
other ALTO resources associated to the Cost Map resource in the same other ALTO resources associated to the Cost Map resource in the same
response. response.
7.1. Media Type 6.1.1. Media Type
The media type of the Multipart Filtered Cost Map Resource is The media type of the Multipart Filtered Cost Map Resource is
"multipart/related;type=application/alto-costmap+json". "multipart/related;type=application/alto-costmap+json".
7.2. HTTP Method 6.1.2. HTTP Method
The Multipart Filtered Cost Map is requested using the HTTP POST The Multipart Filtered Cost Map is requested using the HTTP POST
method. method.
7.3. Accept Input Parameters 6.1.3. Accept Input Parameters
The input parameters of the Multipart Filtered Cost Map MUST be The input parameters of the Multipart Filtered Cost Map are supplied
encoded as a JSON object in the body of an HTTP POST request. The in the body of an HTTP POST request. This document extends the input
media type of the request MUST be one of "application/alto- parameters to a filtered Cost Map with a data format indicated by the
costmapfilter+json". The format of the request body MUST be the same media type "application/alto-costmapfilter+json", which is a JSON
type as defined by section 11.3.2.3 of [RFC7285]. object of type PVReqFilteredCostMap, where:
7.4. Capabilities object {
[PropertyName ane-properties<0..*>;]
} PVReqFilteredCostMap : ReqFilteredCostMap;
with fields:
The Multipart Filtered Cost Map resource uses the same capabilities ane-properties: A list of properties that are associated with the
as defined by section 11.3.2.4 of [RFC7285]. But the "cost-type- ANEs. Each property in this list MUST match one of the supported
names" field SHOULD only includes cost types in "path-vector" cost ANE properties indicated in the resource's "ane-properties"
mode. Otherwise, the ALTO client SHOULD ignore a cost type in other capability. If the field is NOT present, it MUST be interpreted
cost mode, unless additional documents define the specification of it as an empty list, indicating that the ALTO server MUST NOT return
for the Multipart Filtered Cost Map resource. any property in the unified property part.
7.5. Uses 6.1.4. Capabilities
The Multipart Filtered Cost Map resource extends the capabilities
defined in Section 11.3.2.4 of [RFC7285]. The capabilities are
defined by a JSON object of type PVFilteredCostMapCapabilities:
object {
[PropertyName ane-properties<0..*>;]
} PVFilteredCostMapCapabilities : FilteredCostMapCapabilities;
with fields:
cost-type-names: The "cost-type-names" field MUST only include the
path vector cost type, unless explicitly documented by a future
extension. This also implies that the path vector cost type MUST
be defined in the "cost-types" of the Information Resource
Directory's "meta" field.
ane-properties: Defines a list of ANE properties that can be
returned. If the field is NOT present, it MUST be interpreted as
an empty list, indicating the ALTO server CANNOT provide any ANE
property.
6.1.5. Uses
The resource ID of the network map based on which the PIDs in the The resource ID of the network map based on which the PIDs in the
returned cost map will be defined. returned cost map will be defined. If this resource supports
"persistent-entities", it MUST also include ALL the resources that
exposes the entities that MAY appear in the response.
7.6. Response 6.1.6. Response
The response MUST indicate an error, using ALTO protocol error The response MUST indicate an error, using ALTO protocol error
handling, as defined in Section 8.5 of [RFC7285], if the request is handling, as defined in Section 8.5 of [RFC7285], if the request is
invalid. invalid.
The response to a valid request MUST be a "multipart/related" message The "Content-Type" header of the response MUST be "multipart/related"
as defined by [RFC2387]. The body consists of two parts: as defined by [RFC2387] with the following parameters:
o the first part MUST include "Resource-Id" and "Content-Type" in type: The type parameter MUST be "application/alto-costmap+json".
its header. The value of "Resource-Id" MUST be prefixed by the Note that [RFC2387] permits both parameters with and without the
resource id of the Multipart Filtered Cost Map appended by a "." double quotes.
character. The body of this part MUST be a JSON object with the
same format as defined in Section 11.2.3.6 of [RFC7285]; The JSON
object MUST include the "vtag" field in the "meta" field, which
provides the version tag of the returned cost map. The resource
id of the version tag MUST be as same as the value of the
"Resource-Id" header. The "meta" field MUST also include the
"dependent-vtags" field, whose value is a single-element array to
indicate the version tag of the network map used, where the
network map is specified in the "uses" attribute of the Multipart
Cost Map resource in IRD.
o the second part MUST also include "Resource-Id" and "Content-Type" start: The start parameter MUST be a quoted string where the quoted
in its header. The value of "Resource-Id" MUST be prefixed by the part has the same value as the "Resource-ID" header in the first
resource id of the Multipart Filtered Cost Map appended by a "." part.
character. The body of this part MUST be a JSON object with the
same format as defined in Section 4.6 of
[I-D.ietf-alto-unified-props-new]. The JSON object MUST include
the "dependent-vtags" field in the "meta" field. The value of the
"dependent-vtags" field MUST be an array with a single VersionTag
object as defined by section 10.3 of [RFC7285]. The "resource-id"
of this VersionTag MUST be the value of "Resource-Id" header of
the first part. The "tag" of this VersionTag MUST be the "tag" of
"vtag" of the first part body.
8. Multipart Endpoint Cost Service for Path Vector boundary: The boundary parameter is as defined in [RFC2387].
The body of the response consists of two parts.
The first part MUST include "Resource-Id" and "Content-Type" in its
header. The value of "Resource-Id" MUST be prefixed by the resource
id of the Multipart Filtered Cost Map appended by a "." character.
The "Content-Type" MUST be "application/alto-costmap+json".
The body of the first part MUST be a JSON object with the same format
as defined in Section 11.2.3.6 of [RFC7285]. The JSON object MUST
include the "vtag" field in the "meta" field, which provides the
version tag of the returned cost map. The resource id of the version
tag MUST be the same as the value of the "Resource-Id" header. The
"meta" field MUST also include the "dependent-vtags" field, whose
value is a single-element array to indicate the version tag of the
network map used, where the network map is specified in the "uses"
attribute of the Multipart Cost Map resource in IRD.
The second part MUST also include "Resource-Id" and "Content-Type" in
its header. The value of "Resource-Id" MUST be prefixed by the
resource id of the Multipart Filtered Cost Map appended by a "."
character. The "Content-Type" MUST be "application/alto-
propmap+json".
The body of the second part MUST be a JSON object with the same
format as defined in Section 4.6 of
[I-D.ietf-alto-unified-props-new]. The JSON object MUST include the
"dependent-vtags" field in the "meta" field. The value of the
"dependent-vtags" field MUST be an array of VersionTag objects as
defined by Section 10.3 of [RFC7285]. The "vtag" of the first part
MUST be included in the "dependent-vtags". If "persistent-entities"
is requested, the version tags of the dependent resources that MAY
expose the entities in the response MUST also be included. The
PropertyMapData has one member for each ANE identifier that appears
in the first part, where the EntityProps has one member for each
property requested by the client if applicable.
6.2. Multipart Endpoint Cost Service for Path Vector
This document introduces a new ALTO resource called Multipart This document introduces a new ALTO resource called Multipart
Endpoint Cost resource, which allows an ALTO server to provide other Endpoint Cost resource, which allows an ALTO server to provide other
ALTO resources associated to the Endpoint Cost resource in the same ALTO resources associated to the Endpoint Cost resource in the same
response. response.
8.1. Media Type 6.2.1. Media Type
The media type of the Multipart Endpoint Cost Resource is The media type of the Multipart Endpoint Cost Resource is
"multipart/related;type=application/alto-endpointcostmap+json". "multipart/related;type=application/alto-endpointcostmap+json".
8.2. HTTP Method 6.2.2. HTTP Method
The Multipart Endpoint Cost resource is requested using the HTTP POST The Multipart Endpoint Cost resource is requested using the HTTP POST
method. method.
8.3. Accept Input Parameters 6.2.3. Accept Input Parameters
The input parameters of the Multipart Endpoint Cost resource MUST be The input parameters of the Multipart Endpoint Cost resource are
encoded as a JSON object in the body of an HTTP POST request. The supplied in the body of an HTTP POST request. This document extends
media type of the request MUST be one of "application/alto- the input parameters to an Endpoint Cost Map with a data format
endpointcostparams+json". The format of the request body MUST be the indicated by the media type "application/alto-
same type as defined by section 11.5.1.3 of [RFC7285]. endpointcostparams+json", which is a JSON object of type
PVEndpointCostParams, where
8.4. Capabilities object {
[PropertyName ane-properties<0..*>;]
} PVReqEndpointCostMap : ReqEndpointCostMap;
The Multipart Endpoint Cost resource uses the same capabilities as with fields:
defined by section 11.3.2.4 of [RFC7285]. But the "cost-type-names"
field SHOULD only includes cost types in "path-vector" cost mode.
Otherwise, the ALTO client SHOULD ignore a cost type in other cost
mode, unless additional documents define the specification of it for
the Multipart Endpoint Cost resource.
8.5. Uses ane-properties: This document defines the "ane-properties" in
PVReqEndpointCostMap as the same as in PVReqFilteredCostMap. See
Section 6.1.3.
The Multipart Endpoint Cost resource MUST NOT specify the "uses" 6.2.4. Capabilities
attribute.
8.6. Response The capabilities of the Multipart Endpoint Cost Service are defined
by a JSON object of type PVEndpointCostMapCapabilities, which is
defined as the same as PVFilteredCostMapCapabilities. See
Section 6.1.4.
6.2.5. Uses
If a Multipart Endpoint Cost resource supports "persistent-entities",
the "uses" field in its IRD entry MUST include ALL the resources
which exposes the entities that MAY appear in the response.
6.2.6. Response
The response MUST indicate an error, using ALTO protocol error The response MUST indicate an error, using ALTO protocol error
handling, as defined in Section 8.5 of [RFC7285], if the request is handling, as defined in Section 8.5 of [RFC7285], if the request is
invalid. invalid.
The response to a valid request MUST be a "multipart/related" message The "Content-Type" header of the response MUST be "multipart/related"
as defined by [RFC2387]. The body consists of two parts: as defined by [RFC2387] with the following parameters:
o the first part MUST include "Resource-Id" and "Content-Type" in type: The type parameter MUST be "application/alto-
its header. The value of "Resource-Id" MUST be prefixed by the endpointcostmap+json".
resource id of the Multipart Filtered Cost Map appended by a "."
character (U+002E). The body of this part MUST be a JSON object
with the same format as defined in Section 11.5.1.6 of [RFC7285];
The JSON object MUST include the "vtag" field in the "meta" field,
which provides the version tag of the returned endpoint cost map.
The resource id of the version tag MUST be as same as the value of
the "Resource-Id" header.
o the second part MUST also include "Resource-Id" and "Content-Type" start: The start parameter MUST be a quoted string where the quoted
in its header. The value of "Resource-Id" MUST be prefixed by the part has the same value as the "Resource-ID" header in the first
resource id of the Multipart Filtered Cost Map appended by a "." part.
character (U+002E). The body of this part MUST be a JSON object
with the same format as defined in Section 4.6 of
[I-D.ietf-alto-unified-props-new]. The JSON object MUST include
the "dependent-vtags" field in the "meta" field. The value of the
"dependent-vtags" field MUST be an array with a single VersionTag
object as defined by section 10.3 of [RFC7285]. The "resource-id"
of this VersionTag MUST be the value of "Resource-Id" header of
the first part. The "tag" of this VersionTag MUST be the "tag" of
"vtag" of the first part body.
9. Examples boundary: The boundary parameter is as defined in [RFC2387].
The body consists of two parts:
The first part MUST include "Resource-Id" and "Content-Type" in its
header. The value of "Resource-Id" MUST be prefixed by the resource
id of the Multipart Endpoint Cost Service appended by a "." character
(U+002E). The "Content-Type" MUST be "application/alto-
endpointcostmap+json".
The body of the first part MUST be a JSON object with the same format
as defined in Section 11.5.1.6 of [RFC7285]; The JSON object MUST
include the "vtag" field in the "meta" field, which provides the
version tag of the returned endpoint cost map. The resource id of
the version tag MUST be the same as the value of the "Resource-Id"
header.
The second part MUST also include "Resource-Id" and "Content-Type" in
its header. The value of "Resource-Id" MUST be prefixed by the
resource id of the Multipart Filtered Cost Map appended by a "."
character (U+002E). The "Content-Type" MUST be "application/alto-
propmap+json".
The body of the second part MUST be a JSON object with the same
format as defined in Section 4.6 of
[I-D.ietf-alto-unified-props-new]. The JSON object MUST include the
"dependent-vtags" field in the "meta" field. The value of the
"dependent-vtags" field MUST be an array of VersionTag objects as
defined by Section 10.3 of [RFC7285]. The "vtag" of the first part
MUST be included in the "dependent-vtags". If "persistent-entities"
is requested, the version tags of the dependent resources that MAY
expose the entities in the response MUST also be included. The
PropertyMapData has one member for each ANE identifier that appears
in the first part, where the EntityProps has one member for each
property requested by the client if applicable.
7. Examples
This section lists some examples of path vector queries and the This section lists some examples of path vector queries and the
corresponding responses. corresponding responses. Some long lines are truncated for better
readability.
9.1. Information Resource Directory Example 7.1. Information Resource Directory Example
Here is an example of an Information Resource Directory. In this Below is an example of an Information Resource Directory which
example, the "cost-map-pv" information resource provides a Multipart enables the path vector extension. Some critical modifications
Cost Map resource for path-vector; the "endpoint-cost-pv" information include:
resource provides a MultipartEndpoint Cost resource for path-vector.
Both of them support the Maximum Reservable Bandwidth ("maxresbw") o The "path-vector" cost type (Section 5.2) is defined in the "cost-
cost metric in "path-vector" cost mode. types" of the "meta" field.
{ o The "cost-map-pv" information resource provides a Multipart Cost
"meta": { Map resource, which exposes the Maximum Reservable Bandwidth
"cost-types": { ("maxresbw") property.
"pv-maxresbw": {
"cost-mode": "path-vector", o The "http-proxy-props" information resource provides a filtered
"cost-metric": "maxresbw" Unified Property Map resource, which exposes the HTTP proxy entity
} domain (encoded as "http-proxy") and the "price" property. Note
that HTTP proxy is NOT a valid entity domain yet and is used here
only for demonstration.
o The "endpoint-cost-pv" information resource provides a Multipart
Endpoint Cost Service. It exposes the Maximum Reservable
Bandwidth ("maxresbw") property and the Persistent Entity
property. The persistent entities MAY come from the "http-proxy-
props" resource.
o The "update-pv" information resource provides the incremental
update ([I-D.ietf-alto-incr-update-sse]) service for the
"endpoint-cost-pv" resource.
{
"meta": {
"cost-types": {
"path-vector": {
"cost-mode": "array",
"cost-metric": "ane-path"
} }
}
},
"resources": {
"my-default-networkmap": {
"uri" : "http://alto.example.com/networkmap",
"media-type" : "application/alto-networkmap+json"
}, },
"resources": { "cost-map-pv": {
"my-default-networkmap": { "uri": "http://alto.example.com/costmap/pv",
"uri" : "http://alto.example.com/networkmap", "media-type": "multipart/related;
"media-type" : "application/alto-networkmap+json" type=application/alto-costmap+json",
}, "accepts": "application/alto-costmapfilter+json",
"cost-map-pv": { "capabilities": {
"uri": "http://alto.example.com/costmap/pv", "cost-type-names": [ "path-vector" ],
"media-type": `multipart/related; "ane-properties": [ "maxresbw" ]
type=application/alto-costmap+json`,
"accepts": "application/alto-costmapfilter+json",
"capabilities": {
"cost-type-names": [ "pv-maxresbw" ]
},
"uses": [ "my-default-networkmap" ]
}, },
"endpoint-cost-pv": { "uses": [ "my-default-networkmap" ]
"uri": "http://alto.exmaple.com/endpointcost/pv", },
"media-type": `multipart/related; "http-proxy-props": {
type=application/alto-endpointcost+json`, "uri": "http://alto.example.com/proxy-props",
"accepts": "application/alto-endpointcostparams+json", "media-type": "application/alto-propmap+json",
"capabilities": { "accpets": "application/alto-propmapparams+json",
"cost-type-names": [ "pv-maxresbw" ] "capabilities": {
"mappings": {
"http-proxy": [ "price" ]
} }
}
},
"endpoint-cost-pv": {
"uri": "http://alto.exmaple.com/endpointcost/pv",
"media-type": "multipart/related;
type=application/alto-endpointcost+json",
"accepts": "application/alto-endpointcostparams+json",
"capabilities": {
"cost-type-names": [ "path-vector" ],
"ane-properties": [ "maxresbw", "persistent-entities" ]
}, },
"update-pv": { "uses": [ "http-proxy-props" ]
"uri": "http://alto.example.com/updates/pv", },
"media-type": "text/event-stream", "update-pv": {
"uses": [ "endpoint-cost-pv" ], "uri": "http://alto.example.com/updates/pv",
"accepts": "application/alto-updatestreamparams+json", "media-type": "text/event-stream",
"capabilities": { "uses": [ "endpoint-cost-pv" ],
"support-stream-control": true "accepts": "application/alto-updatestreamparams+json",
} "capabilities": {
"support-stream-control": true
} }
} }
} }
}
9.2. Example #1 7.2. Example: Multipart Filtered Cost Map
Query filtered cost map to get the path vectors. The following examples demonstrate the request to the "cost-map-pv"
resource and the corresponding response.
The request uses the path vector cost type in the "cost-type" field.
The "ane-properties" field is missing, indicating that the client
only requests for the path vector but not the ANE properties.
The response consists of two parts. The first part returns the array
of ANE identifiers for each source and destination pair. There are
three ANEs, where "ane:L001" is shared by traffic from "PID1" to both
"PID2" and "PID3".
The second part returns an empty property map. Note that the ANE
entries are omitted since they have no properties (See Section 3.1 of
[I-D.ietf-alto-unified-props-new]).
POST /costmap/pv HTTP/1.1 POST /costmap/pv HTTP/1.1
Host: alto.example.com Host: alto.example.com
Accept: multipart/related; Accept: multipart/related;type=application/alto-costmap+json,
type=application/alto-costmap+json,
application/alto-error+json application/alto-error+json
Content-Length: [TBD] Content-Length: [TBD]
Content-Type: application/alto-costmapfilter+json Content-Type: application/alto-costmapfilter+json
{ {
"cost-type": { "cost-type": {
"cost-mode": "path-vector", "cost-mode": "array",
"cost-metric": "maxresbw" "cost-metric": "ane-path"
}, },
"pids": { "pids": {
"srcs": [ "PID1" ], "srcs": [ "PID1" ],
"dsts": [ "PID2", "PID3" ] "dsts": [ "PID2", "PID3" ]
} }
} }
HTTP/1.1 200 OK HTTP/1.1 200 OK
Content-Length: [TBD] Content-Length: [TBD]
Content-Type: multipart/related; boundary=example-1; Content-Type: multipart/related;
start=cost-map-pv.costmap boundary=example-1;
start=cost-map-pv.costmap;
type=application/alto-costmap+json type=application/alto-costmap+json
--example-1 --example-1
Resource-Id: cost-map-pv.costmap Resource-Id: cost-map-pv.costmap
Content-Type: application/alto-costmap+json Content-Type: application/alto-costmap+json
{ {
"meta": { "meta": {
"vtag": { "vtag": {
"resource-id": "cost-map-pv.costmap", "resource-id": "cost-map-pv.costmap",
"tag": "d827f484cb66ce6df6b5077cb8562b0a" "tag": "d827f484cb66ce6df6b5077cb8562b0a"
}, },
"dependent-vtags": [ "dependent-vtags": [
{ {
"resource-id": "my-default-networkmap", "resource-id": "my-default-networkmap",
"tag": "75ed013b3cb58f896e839582504f6228" "tag": "75ed013b3cb58f896e839582504f6228"
} }
], ],
"cost-type": { "cost-type": {
"cost-mode": "path-vector", "cost-mode": "array",
"cost-metric": "maxresbw" "cost-metric": "ane-path"
} }
}, },
"cost-map": { "cost-map": {
"PID1": { "PID1": {
"PID2": [ "ane:L001", "ane:L003" ], "PID2": [ "ane:L001", "ane:L003" ],
"PID3": [ "ane:L001", "ane:L004" ] "PID3": [ "ane:L001", "ane:L004" ]
} }
} }
} }
--example-1 --example-1
skipping to change at page 17, line 28 skipping to change at page 20, line 41
{ {
"meta": { "meta": {
"dependent-vtags": [ "dependent-vtags": [
{ {
"resource-id": "cost-map-pv.costmap", "resource-id": "cost-map-pv.costmap",
"tag": "d827f484cb66ce6df6b5077cb8562b0a" "tag": "d827f484cb66ce6df6b5077cb8562b0a"
} }
] ]
}, },
"property-map": { "property-map": {
"ane:L001": { "maxresbw": 100000000},
"ane:L003": { "maxresbw": 150000000},
"ane:L004": { "maxresbw": 50000000}
} }
} }
9.3. Example #2 7.3. Example: Multipart Endpoint Cost Service
The following examples demonstrate the request to the "endpoint-cost-
pv" resource and the corresponding response.
The request uses the path vector cost type in the "cost-type" field,
and queries the Maximum Reservable Bandwidth ANE property and the
Persistent Entity property.
The response consists of two parts. The first part returns the array
of ANE identifiers for each valid source and destination pair.
The second part returns the requested properties of ANEs in the first
part. The "ane:NET001" element contains an HTTP proxy entity, which
can be further used by the client. Since it does not contain a
"maxresbw" property, the client SHOULD assume it does NOT support
bandwidth reservation but will NOT become a traffic bottleneck, as
specified in Section 5.4.1.
POST /endpointcost/pv HTTP/1.1 POST /endpointcost/pv HTTP/1.1
Host: alto.example.com Host: alto.example.com
Accept: multipart/related; Accept: multipart/related;
type=application/alto-endpointcost+json, type=application/alto-endpointcost+json,
application/alto-error+json application/alto-error+json
Content-Length: [TBD] Content-Length: [TBD]
Content-Type: application/alto-endpointcostparams+json Content-Type: application/alto-endpointcostparams+json
{ {
"cost-type": { "cost-type": {
"cost-mode": "path-vector", "cost-mode": "array",
"cost-metric": "maxresbw" "cost-metric": "ane-path"
}, },
"endpoints": { "endpoints": {
"srcs": [ "ipv4:192.0.2.2" ], "srcs": [ "ipv4:192.0.2.2" ],
"dsts": [ "ipv4:192.0.2.89", "dsts": [ "ipv4:192.0.2.89",
"ipv4:203.0.113.45", "ipv4:203.0.113.45",
"ipv6:2001:db8::10" ] "ipv6:2001:db8::10" ]
} },
"ane-properties": [ "maxresbw", "persistent-entities" ]
} }
HTTP/1.1 200 OK HTTP/1.1 200 OK
Content-Length: [TBD] Content-Length: [TBD]
Content-Type: multipart/related; boundary=example-2; Content-Type: multipart/related; boundary=example-2;
start=endpoint-cost-pv.ecs start=endpoint-cost-pv.ecs;
type=application/alto-endpointcost+json type=application/alto-endpointcost+json
--example-2 --example-2
Resource-Id: endpoint-cost-pv.ecs Resource-Id: endpoint-cost-pv.ecs
Content-Type: application/alto-endpointcost+json Content-Type: application/alto-endpointcost+json
{ {
"meta": { "meta": {
"vtags": { "vtags": {
"resource-id": "endpoint-cost-pv.ecs", "resource-id": "endpoint-cost-pv.ecs",
"tag": "bb6bb72eafe8f9bdc4f335c7ed3b10822a391cef" "tag": "bb6bb72eafe8f9bdc4f335c7ed3b10822a391cef"
}, },
"cost-type": { "cost-type": {
"cost-mode": "path-vector", "cost-mode": "array",
"cost-metric": "maxresbw" "cost-metric": "ane-path"
} }
}, },
"endpoint-cost-map": { "endpoint-cost-map": {
"ipv4:192.0.2.2": { "ipv4:192.0.2.2": {
"ipv4:192.0.2.89": [ "ane:L001", "ane:L003", "ipv4:192.0.2.89": [ "ane:NET001", "ane:L002" ],
"ane:L004" ], "ipv4:203.0.113.45": [ "ane:NET001", "ane:L003" ]
"ipv4:203.0.113.45": [ "ane:L001", "ane:L004",
"ane:L005" ],
"ipv6:2001:db8::10": [ "ane:L001", "ane:L005",
"ane:L007" ]
} }
} }
} }
--example-2 --example-2
Resource-Id: endpoint-cost-pv.propmap Resource-Id: endpoint-cost-pv.propmap
Content-Type: application/alto-propmap+json Content-Type: application/alto-propmap+json
{ {
"meta": { "meta": {
"dependent-vtags": [ "dependent-vtags": [
{ {
"resource-id": "endpoint-cost-pv.ecs", "resource-id": "endpoint-cost-pv.ecs",
"tag": "bb6bb72eafe8f9bdc4f335c7ed3b10822a391cef" "tag": "bb6bb72eafe8f9bdc4f335c7ed3b10822a391cef"
},
{
"resource-id": "http-proxy-props",
"tag": "bf3c8c1819d2421c9a95a9d02af557a3"
} }
] ]
}, },
"property-map": { "property-map": {
"ane:L001": { "maxresbw": 50000000 }, "ane:NET001": {
"ane:L003": { "maxresbw": 48000000 }, "persistent-entities": [ "http-proxy:192.0.2.1" ]
"ane:L004": { "maxresbw": 55000000 }, },
"ane:L005": { "maxresbw": 60000000 }, "ane:L002": { "maxresbw": 48000000 },
"ane:L007": { "maxresbw": 35000000 } "ane:L003": { "maxresbw": 35000000 }
} }
} }
9.4. Example for Incremental Update 7.4. Example: Incremental Updates
In this example, an ALTO client subscribe the incremental update for In this example, an ALTO client subscribes to the incremental update
the Multipart Endpoint Cost resource "endpoint-cost-pv". for the Multipart Endpoint Cost resource "endpoint-cost-pv".
POST /updates/pv HTTP/1.1 POST /updates/pv HTTP/1.1
Host: alto.example.com Host: alto.example.com
Accept: text/event-stream Accept: text/event-stream
Content-Type: application/alto-updatestreamparams+json Content-Type: application/alto-updatestreamparams+json
Content-Length: [TBD] Content-Length: [TBD]
{ {
"add": { "add": {
"ecspvsub1": { "ecspvsub1": {
"resource-id": "endpoint-cost-pv", "resource-id": "endpoint-cost-pv",
"input": <ecs-input> "input": <ecs-input>
} }
} }
} }
Based on the server process defined in
Based on the server-side process defined in
[I-D.ietf-alto-incr-update-sse], the ALTO server will send the [I-D.ietf-alto-incr-update-sse], the ALTO server will send the
control-uri first using Server-Sent Event (SSE), and follow the full "control-uri" first using Server-Sent Event (SSE), followed by the
response of the multipart message. full response of the multipart message.
HTTP/1.1 200 OK HTTP/1.1 200 OK
Connection: keep-alive Connection: keep-alive
Content-Type: text/event-stream Content-Type: text/event-stream
event: application/alto-updatestreamcontrol+json event: application/alto-updatestreamcontrol+json
data: {"control-uri": "http://alto.example.com/updates/streams/1414"} data: {"control-uri": "http://alto.example.com/updates/streams/1414"}
event: multipart/related;boundary=example-3;start=pvmap; event: multipart/related;boundary=example-3;start=pvmap;
type=application/alto-endpointcost+json,ecspvsub1 type=application/alto-endpointcost+json,ecspvsub1
data: --example-3 data: --example-3
data: Content-ID: pvmap data: Resource-ID: endpoint-cost-pv.ecsmap02695067
data: Content-Type: application/alto-endpointcost+json data: Content-Type: application/alto-endpointcost+json
data: data:
data: <endpoint-cost-map-entry> data: <endpoint-cost-map-entry>
data: --example-3 data: --example-3
data: Content-ID: nepmap data: Resource-ID: endpoint-cost-pv.propmapbbc868aa
data: Content-Type: application/alto-propmap+json data: Content-Type: application/alto-propmap+json
data: data:
data: <property-map-entry> data: <property-map-entry>
data: --example-3-- data: --example-3--
Then, the ALTO server will subscribe the whole tree of the multipart When the contents change, the ALTO server will publish the updates
message automatically.
When the data updated, the ALTO server will publish the data updates
for each node in this tree separately. for each node in this tree separately.
event: application/merge-patch+json,ecspvsub1.pvmap event: application/merge-patch+json,
ecspvsub1.endpoint-cost-pv.ecsmap02695067
data: <Merge patch for endpoint-cost-map-update> data: <Merge patch for endpoint-cost-map-update>
event: application/merge-patch+json,ecspvsub2.nepmap event: application/merge-patch+json,
ecspvsub1.endpoint-cost-pv.propmapbbc868aa
data: <Merge patch for property-map-update> data: <Merge patch for property-map-update>
10. Compatibility 8. Compatibility
10.1. Compatibility with Base ALTO Clients/Servers 8.1. Compatibility with Base ALTO Clients/Servers
The Multipart Filtered Cost Map resource and the Multipart Endpoint The Multipart Filtered Cost Map resource and the Multipart Endpoint
Cost resource has no backward compatibility issue with the base ALTO Cost resource has no backward compatibility issue with the base ALTO
clients and servers. Although these two types of resources reuse the clients and servers. Although these two types of resources reuse the
media types defined in the base ALTO protocol for the accept input media types defined in the base ALTO protocol for the accept input
parameters, they have different media types for responses. If the parameters, they have different media types for responses. If the
ALTO server provides these two types of resources, but the ALTO ALTO server provides these two types of resources, but the ALTO
client does not support them, the ALTO client will ignore the client does not support them, the ALTO client will ignore the
resources without conducting any incompatibility. resources without conducting any incompatibility.
10.2. Compatibility with Multi-Cost Extension 8.2. Compatibility with Multi-Cost Extension
This document does not specify how to integrate the "path-vector" This document does not specify how to integrate the "path-vector"
cost mode with the multi-cost extension [RFC8189]. Although there is cost mode with the multi-cost extension [RFC8189]. Although there is
no reason why somebody has to compound the path vectors with other no reason why somebody has to compound the path vectors with other
cost types in a single query, there is no compatible issue doing it cost types in a single query, there is no compatible issue doing it
without constraint tests. without constraint tests.
10.3. Compatibility with Incremental Update 8.3. Compatibility with Incremental Update
As this document still follows the basic request/response protocol As this document still follows the basic request/response protocol
with JSON encoding, it is surely compatible with the incremental with JSON encoding, it is surely compatible with the incremental
update service as defined by [I-D.ietf-alto-incr-update-sse]. But update service as defined by [I-D.ietf-alto-incr-update-sse]. But
the following details are to be noticed: the following details are to be noticed:
o When using the compound response, updates on both cost map and o When using the compound response, updates on both cost map and
property map SHOULD be notified. property map SHOULD be notified.
o When not using the compound response, because the cost map is in o When not using the compound response, because the cost map is in
the "uses" attribute of the property map, once the path vectors in the "uses" attribute of the property map, once the path vectors in
the cost map change, the ALTO server MUST send the updates of the the cost map change, the ALTO server MUST send the updates of the
cost map before the updates of the property map. cost map before the updates of the property map.
11. General Discussions 9. General Discussions
11.1. Provide Calendar for Property Map 9.1. Provide Calendar for Property Map
Fetching the historical network information is useful for many Fetching the historical network information is useful for many
traffic optimization problem. [I-D.ietf-alto-cost-calendar] already traffic optimization problem. [I-D.ietf-alto-cost-calendar] already
proposes an ALTO extension called Cost Calendar which provides the proposes an ALTO extension called Cost Calendar which provides the
historical cost values using Filtered Cost Map and Endpoint Cost historical cost values using Filtered Cost Map and Endpoint Cost
Service. However, the calendar for only path costs is not enough. Service. However, the calendar for only path costs is not enough.
For example, as the properties of ANEs (e.g., available bandwidth and For example, as the properties of ANEs (e.g., available bandwidth and
link delay) are usually the real-time network states, they change link delay) are usually the real-time network states, they change
frequently in the real network. It is very helpful to get the frequently in the real network. It is very helpful to get the
historical value of these properties. Applications may predicate the historical value of these properties. Applications may predicate the
network status using these information to better optimize their network status using these information to better optimize their
performance. performance.
So the coming requirement may be a general calendar service for the So the coming requirement may be a general calendar service for the
ALTO information resources. ALTO information resources.
11.2. Constraint Tests for General Cost Types 9.2. Constraint Tests for General Cost Types
The constraint test is a simple approach to query the data. It The constraint test is a simple approach to query the data. It
allows users to filter the query result by specifying some boolean allows users to filter the query result by specifying some boolean
tests. This approach is already used in the ALTO protocol. tests. This approach is already used in the ALTO protocol.
[RFC7285] and [RFC8189] allow ALTO clients to specify the [RFC7285] and [RFC8189] allow ALTO clients to specify the
"constraints" and "or-constraints" tests to better filter the result. "constraints" and "or-constraints" tests to better filter the result.
However, the current defined syntax is too simple and can only be However, the current defined syntax is too simple and can only be
used to test the scalar cost value. For more complex cost types, used to test the scalar cost value. For more complex cost types,
like the "array" mode defined in this document, it does not work like the "array" mode defined in this document, it does not work
well. It will be helpful to propose more general constraint tests to well. It will be helpful to propose more general constraint tests to
better perform the query. better perform the query.
In practice, it is too complex to customize a language for the In practice, it is too complex to customize a language for the
general-purpose boolean tests, and can be a duplicated work. So it general-purpose boolean tests, and can be a duplicated work. So it
may be a good idea to integrate some already defined and widely used may be a good idea to integrate some already defined and widely used
query languages (or their subset) to solve this problem. The query languages (or their subset) to solve this problem. The
candidates can be XQuery and JSONiq. candidates can be XQuery and JSONiq.
11.3. General Multipart Resources Query 9.3. General Multipart Resources Query
Querying multiple ALTO information resources continuously MAY be a Querying multiple ALTO information resources continuously MAY be a
general requirement. And the coming issues like inefficiency and general requirement. And the coming issues like inefficiency and
inconsistency are also general. There is no standard solving these inconsistency are also general. There is no standard solving these
issues yet. So we need some approach to make the ALTO client request issues yet. So we need some approach to make the ALTO client request
the compound ALTO information resources in a single query. the compound ALTO information resources in a single query.
12. Security Considerations 10. Security Considerations
This document is an extension of the base ALTO protocol, so the This document is an extension of the base ALTO protocol, so the
Security Considerations [RFC7285] of the base ALTO protocol fully Security Considerations [RFC7285] of the base ALTO protocol fully
apply when this extension is provided by an ALTO server. apply when this extension is provided by an ALTO server.
The path vector extension requires additional considerations on two The path vector extension requires additional considerations on two
security considerations discussed in the base protocol: security considerations discussed in the base protocol:
confidentiality of ALTO information (Section 15.3 of [RFC7285]) and confidentiality of ALTO information (Section 15.3 of [RFC7285]) and
availability of ALTO service (Section 15.5 of [RFC7285]). availability of ALTO service (Section 15.5 of [RFC7285]).
skipping to change at page 23, line 33 skipping to change at page 27, line 5
Even if there is no intentional attack, the dependent property map of Even if there is no intentional attack, the dependent property map of
path vector might be still dynamically enriched, in that every new path vector might be still dynamically enriched, in that every new
request for path vectors will make the ALTO server generate a new request for path vectors will make the ALTO server generate a new
property map. So the properties of the abstract network elements can property map. So the properties of the abstract network elements can
consume a large amount of resources when cached. To avoid this, the consume a large amount of resources when cached. To avoid this, the
ALTO server providing the path vector extension should support a ALTO server providing the path vector extension should support a
time-to-live configuration for the property map, so that the outdated time-to-live configuration for the property map, so that the outdated
entries can be removed from the property map resource. entries can be removed from the property map resource.
13. IANA Considerations 11. IANA Considerations
13.1. ALTO Cost Mode Registry 11.1. ALTO Cost Mode Registry
This document specifies a new cost mode "path-vector". However, the This document specifies a new cost mode "path-vector". However, the
base ALTO protocol does not have a Cost Mode Registry where new cost base ALTO protocol does not have a Cost Mode Registry where new cost
mode can be registered. This new cost mode will be registered once mode can be registered. This new cost mode will be registered once
the registry is defined either in a revised version of [RFC7285] or the registry is defined either in a revised version of [RFC7285] or
in another future extension. in another future extension.
13.2. ALTO Entity Domain Registry 11.2. ALTO Entity Domain Registry
As proposed in Section 9.2 of [I-D.ietf-alto-unified-props-new], As proposed in Section 9.2 of [I-D.ietf-alto-unified-props-new],
"ALTO Domain Entity Registry" is requested. Besides, a new domain is "ALTO Domain Entity Registry" is requested. Besides, a new domain is
to be registered, listed in Table 1. to be registered, listed in Table 1.
+-------------+--------------------------+--------------------------+ +-------------+--------------------------+--------------------------+
| Identifier | Entity Address Encoding | Hierarchy & Inheritance | | Identifier | Entity Address Encoding | Hierarchy & Inheritance |
+-------------+--------------------------+--------------------------+ +-------------+--------------------------+--------------------------+
| ane | See Section 6.2 | None | | ane | See Section 5.3.2 | None |
+-------------+--------------------------+--------------------------+ +-------------+--------------------------+--------------------------+
Table 1: ALTO Entity Domain Table 1: ALTO Entity Domain
13.3. ALTO Property Type Registry 11.3. ALTO Property Type Registry
The "ALTO Property Type Registry" is required by the ALTO Domain The "ALTO Property Type Registry" is required by the ALTO Domain
"ane", listed in Table 2. "ane", listed in Table 2.
+-------------+------------+----------------------------------------+ +-------------+------------+----------------------------------------+
| Identifier | Intended | Dependencies and Interpretation | | Identifier | Intended | Dependencies and Interpretation |
| | Semantics | | | | Semantics | |
+-------------+------------+----------------------------------------+ +-------------+------------+----------------------------------------+
| ane:maxresb | The | application/alto-costmap+json, or | | ane:maxresb | The | application/alto-costmap+json, or |
| w | maximum | application/alto-endpointcostmap+json, | | w | maximum | application/alto-endpointcostmap+json, |
| | reservable | where the ANE names are used. | | | reservable | where the ANE names are used. |
| | bandwidth | | | | bandwidth | |
| | for the | | | | for the | |
| | ANE | | | | ANE | |
+-------------+------------+----------------------------------------+ +-------------+------------+----------------------------------------+
Table 2: ALTO Abstract Network Element Property Types Table 2: ALTO Abstract Network Element Property Types
14. Acknowledgments 12. Acknowledgments
The authors would like to thank discussions with Andreas Voellmy, The authors would like to thank discussions with Andreas Voellmy,
Erran Li, Haibin Son, Haizhou Du, Jiayuan Hu, Qiao Xiang, Tianyuan Erran Li, Haibin Son, Haizhou Du, Jiayuan Hu, Qiao Xiang, Tianyuan
Liu, Xiao Shi, Xin Wang, and Yan Luo. The authors thank Greg Liu, Xiao Shi, Xin Wang, and Yan Luo. The authors thank Greg
Bernstein (Grotto Networks), Dawn Chen (Tongji University), Wendy Bernstein (Grotto Networks), Dawn Chen (Tongji University), Wendy
Roome, and Michael Scharf for their contributions to earlier drafts. Roome, and Michael Scharf for their contributions to earlier drafts.
15. References 13. References
15.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
15.2. Informative References
[I-D.bernstein-alto-topo]
Bernstein, G., Yang, Y., and Y. Lee, "ALTO Topology
Service: Uses Cases, Requirements, and Framework", draft-
bernstein-alto-topo-00 (work in progress), October 2013.
[I-D.ietf-alto-cost-calendar] 13.1. Normative References
Randriamasy, S., Yang, Y., Wu, Q., Lingli, D., and N.
Schwan, "ALTO Cost Calendar", draft-ietf-alto-cost-
calendar-01 (work in progress), February 2017.
[I-D.ietf-alto-incr-update-sse] [I-D.ietf-alto-incr-update-sse]
Roome, W. and Y. Yang, "ALTO Incremental Updates Using Roome, W. and Y. Yang, "ALTO Incremental Updates Using
Server-Sent Events (SSE)", draft-ietf-alto-incr-update- Server-Sent Events (SSE)", draft-ietf-alto-incr-update-
sse-16 (work in progress), March 2019. sse-16 (work in progress), March 2019.
[I-D.ietf-alto-performance-metrics]
Wu, Q., Yang, Y., Lee, Y., Dhody, D., and S. Randriamasy,
"ALTO Performance Cost Metrics", draft-ietf-alto-
performance-metrics-06 (work in progress), November 2018.
[I-D.ietf-alto-unified-props-new] [I-D.ietf-alto-unified-props-new]
Roome, W., Randriamasy, S., Yang, Y., and J. Zhang, Roome, W., Randriamasy, S., Yang, Y., and J. Zhang,
"Unified Properties for the ALTO Protocol", draft-ietf- "Unified Properties for the ALTO Protocol", draft-ietf-
alto-unified-props-new-07 (work in progress), March 2019. alto-unified-props-new-07 (work in progress), March 2019.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2387] Levinson, E., "The MIME Multipart/Related Content-type", [RFC2387] Levinson, E., "The MIME Multipart/Related Content-type",
RFC 2387, DOI 10.17487/RFC2387, August 1998, RFC 2387, DOI 10.17487/RFC2387, August 1998,
<https://www.rfc-editor.org/info/rfc2387>. <https://www.rfc-editor.org/info/rfc2387>.
[RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S., [RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S.,
Previdi, S., Roome, W., Shalunov, S., and R. Woundy, Previdi, S., Roome, W., Shalunov, S., and R. Woundy,
"Application-Layer Traffic Optimization (ALTO) Protocol", "Application-Layer Traffic Optimization (ALTO) Protocol",
RFC 7285, DOI 10.17487/RFC7285, September 2014, RFC 7285, DOI 10.17487/RFC7285, September 2014,
<https://www.rfc-editor.org/info/rfc7285>. <https://www.rfc-editor.org/info/rfc7285>.
[RFC8189] Randriamasy, S., Roome, W., and N. Schwan, "Multi-Cost [RFC8189] Randriamasy, S., Roome, W., and N. Schwan, "Multi-Cost
Application-Layer Traffic Optimization (ALTO)", RFC 8189, Application-Layer Traffic Optimization (ALTO)", RFC 8189,
DOI 10.17487/RFC8189, October 2017, DOI 10.17487/RFC8189, October 2017,
<https://www.rfc-editor.org/info/rfc8189>. <https://www.rfc-editor.org/info/rfc8189>.
13.2. Informative References
[I-D.bernstein-alto-topo]
Bernstein, G., Yang, Y., and Y. Lee, "ALTO Topology
Service: Uses Cases, Requirements, and Framework", draft-
bernstein-alto-topo-00 (work in progress), October 2013.
[I-D.ietf-alto-cost-calendar]
Randriamasy, S., Yang, Y., Wu, Q., Lingli, D., and N.
Schwan, "ALTO Cost Calendar", draft-ietf-alto-cost-
calendar-01 (work in progress), February 2017.
[I-D.ietf-alto-performance-metrics]
Wu, Q., Yang, Y., Lee, Y., Dhody, D., and S. Randriamasy,
"ALTO Performance Cost Metrics", draft-ietf-alto-
performance-metrics-06 (work in progress), November 2018.
Authors' Addresses Authors' Addresses
Kai Gao Kai Gao
Tsinghua University Sichuan University
Beijing Beijing Chengdu 610000
China China
Email: gaok12@mails.tsinghua.edu.cn Email: kai.gao@scu.edu.cn
Young Lee Young Lee
Huawei Huawei
TX TX
USA USA
Email: leeyoung@huawei.com Email: leeyoung@huawei.com
Sabine Randriamasy Sabine Randriamasy
Nokia Bell Labs Nokia Bell Labs
 End of changes. 116 change blocks. 
349 lines changed or deleted 536 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/