draft-ietf-rserpool-overview-00.txt   draft-ietf-rserpool-overview-01.txt 
Network Working Group P. Lei Network Working Group P. Lei
Internet-Draft Cisco Systems, Inc. Internet-Draft Cisco Systems, Inc.
Intended status: Informational L. Ong Intended status: Informational L. Ong
Expires: April 18, 2007 Ciena Corporation Expires: October 30, 2007 Ciena Corporation
M. Tuexen M. Tuexen
Muenster Univ. of Applied Sciences Muenster Univ. of Applied Sciences
October 15, 2006 April 28, 2007
An Overview of Reliable Server Pooling Protocols An Overview of Reliable Server Pooling Protocols
draft-ietf-rserpool-overview-00.txt draft-ietf-rserpool-overview-01.txt
Status of this Memo Status of this Memo
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Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
Abstract Abstract
The Reliable Server Pooling effort (abbreviated "RSerPool"), provides The Reliable Server Pooling effort (abbreviated "RSerPool"), provides
an application-independent set of services and protocols for building an application-independent set of services and protocols for building
fault tolerant and highly available client/server applications. This fault tolerant and highly available client/server applications. This
document provides an overview of the protocols and mechanisms in the document provides an overview of the protocols and mechanisms in the
reliable server pooling suite. reliable server pooling suite.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. ASAP Overview . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Aggregate Server Access Protocol (ASAP) Overview . . . . . . . 5
2.1. Pool Initialization . . . . . . . . . . . . . . . . . . . 5 2.1. Pool Initialization . . . . . . . . . . . . . . . . . . . 5
2.2. Pool Entity Registration . . . . . . . . . . . . . . . . . 5 2.2. Pool Entity Registration . . . . . . . . . . . . . . . . . 5
2.3. Pool Entity Selection . . . . . . . . . . . . . . . . . . 5 2.3. Pool Entity Selection . . . . . . . . . . . . . . . . . . 6
2.4. Endpoint Keepalive . . . . . . . . . . . . . . . . . . . . 6 2.4. Endpoint Keepalive . . . . . . . . . . . . . . . . . . . . 6
2.5. Failover Services . . . . . . . . . . . . . . . . . . . . 6 2.5. Failover Services . . . . . . . . . . . . . . . . . . . . 6
2.5.1. Cookie Mechanism . . . . . . . . . . . . . . . . . . . 6 2.5.1. Cookie Mechanism . . . . . . . . . . . . . . . . . . . 6
2.5.2. Business Card Mechanism . . . . . . . . . . . . . . . 6 2.5.2. Business Card Mechanism . . . . . . . . . . . . . . . 7
2.5.3. Failover Callback Mechanism . . . . . . . . . . . . . 7 3. Endpoint Nameserver Redundancy Protocol (ENRP) Overview . . . 7
3. ENRP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. Initialization . . . . . . . . . . . . . . . . . . . . . . 7 3.1. Initialization . . . . . . . . . . . . . . . . . . . . . . 7
3.2. Server Discovery . . . . . . . . . . . . . . . . . . . . . 7 3.2. Server Discovery and Home Server Selection . . . . . . . . 7
3.3. Server Pool Maintenance . . . . . . . . . . . . . . . . . 8 3.3. Server Pool Maintenance . . . . . . . . . . . . . . . . . 8
4. Example Scenarios . . . . . . . . . . . . . . . . . . . . . . 8 4. Example Scenarios . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Example Scenario Using RSerPool Resolution Service . . . . 8 4.1. Example Scenario Using RSerPool Resolution Service . . . . 8
4.1.1. Standalone Mode . . . . . . . . . . . . . . . . . . . 8
4.1.2. Pool Mode . . . . . . . . . . . . . . . . . . . . . . 8
4.2. Example Scenario Using RSerPool Session Services . . . . . 9 4.2. Example Scenario Using RSerPool Session Services . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
8. Normative References . . . . . . . . . . . . . . . . . . . . . 11 8. Normative References . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . . . 13 Intellectual Property and Copyright Statements . . . . . . . . . . 13
1. Introduction 1. Introduction
The requirements for the Reliable Server Pooling effort are defined The Reliable Server Pooling (RSerPool) protocol suite is designed to
in RFC3237 [2]. The central idea of this architecture is to provide provide client applications ("pool users") with the ability to select
client applications ("pool users") with the ability to select a a server (a "pool element") from among a group of servers providing
server (a "pool element") from among a group of servers providing equivalent service (a "pool").
equivalent service (a "pool"). The pool is accessed via an
identifier called a "pool handle", which is a location-independent
name separate from the IP address of any pool server.
The RSerPool architecture supports high-availability and load The RSerPool architecture supports high-availability and load
balancing by enabling a pool user to identify the most appropriate balancing by enabling a pool user to identify the most appropriate
server from the server pool at a given time. The architecture is server from the server pool at a given time. The architecture is
defined to support a set of basic goals: defined to support a set of basic goals:
o application-independent protocol mechanisms o application-independent protocol mechanisms
o separation of server naming from IP addressing o separation of server naming from IP addressing
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. +-------+ . . +-------+ .
....................... .......................
Figure 1 Figure 1
A server pool is defined as a set of one or more servers providing A server pool is defined as a set of one or more servers providing
the same application functionality. The servers are called Pool the same application functionality. The servers are called Pool
Elements (PEs). Multiple PEs in a server pool can be used to provide Elements (PEs). Multiple PEs in a server pool can be used to provide
fault tolerance or load sharing, for example. The PEs register into fault tolerance or load sharing, for example. The PEs register into
and deregisters out of the pool using the Aggregate Server Access and deregisters out of the pool using the Aggregate Server Access
Protocol ASAP [3]. Protocol ASAP [2].
Each server pool is identified by a unique byte string called the Each server pool is identified by a unique byte string called the
pool handle. The pool handle allows a mapping from the pool to a pool handle. The pool handle allows a mapping from the pool to a
specific Pool Element located by its IP address and port. The pool specific Pool Element located by its IP address and port. The pool
handle is what is specified by the Pool User (PU) when it attempts to handle is what is specified by the Pool User (PU) when it attempts to
access a server in the pool, again using ASAP. Both IPv4 and IPv6 PE access a server in the pool, again using ASAP. Both IPv4 and IPv6 PE
addresses are supported. addresses are supported.
To resolve the pool handle to the address necessary to access a Pool To resolve the pool handle to the address necessary to access a Pool
Element, the PU consults an entity called the Endpoint haNdlespace Element, the PU consults an entity called the Endpoint haNdlespace
Redundancy Protocol (ENRP) server. This server may be a standalone Redundancy Protocol (ENRP) server. This server may be a standalone
server supporting many PUs or a part of the PU itself, however it is server supporting many PUs or a part of the PU itself, however it is
envisioned that ENRP servers provide a fully distributed and fault- envisioned that ENRP servers provide a fully distributed and fault-
tolerant registry service using ENRP [4] to maintain synchronization tolerant registry service using ENRP [3] to maintain synchronization
of data concerning the pool handle mapping space. of data concerning the pool handle mapping space.
Rserpool provides a number of tools to aid client migration between
servers on server failure: it allows the client to identify
alternative servers, either on initial discovery or in real time; it
also allows the original server to provide a state cookie to the
client that can be forwarded to an alternative server to provide
application-specific state information.
The requirements for the Reliable Server Pooling effort are defined
in RFC3237 [1].
This document provides an overview of the RSerPool protocol suite, This document provides an overview of the RSerPool protocol suite,
specifically the Aggregate Server Access Protocol ASAP [3] and the specifically the Aggregate Server Access Protocol ASAP [2] and the
Endpoint Nameserver Redundancy Protocol ENRP [4]. Endpoint Nameserver Redundancy Protocol ENRP [3].
In addition to the protocol specifications, there is a common In addition to the protocol specifications, there is a common
parameter format specification COMMON [5] for both protocols, as well parameter format specification COMMON [4] for both protocols, as well
as a security threat analysis SEC [6]. as a security threat analysis SEC [5].
2. ASAP Overview 2. Aggregate Server Access Protocol (ASAP) Overview
ASAP is a straight-forward implementation of a set of mechanisms ASAP is a straight-forward implementation of a set of mechanisms
identified as necessary for support of the creation and maintenance identified as necessary for support of the creation and maintenance
of pools of redundant servers. These mechanisms include: of pools of redundant servers. These mechanisms include:
o registration of a new server for the server pool o registration of a new server for the server pool
o deregistration of an existing server in the pool o deregistration of an existing server from the pool
o resolution of a pool 'handle' to a server or list o resolution of a pool 'handle' to a server or list of servers
o liveness detection for servers in the pool o liveness detection for servers in the pool
o failover mechanisms for handling server failure o failover mechanisms for handling server failure
2.1. Pool Initialization 2.1. Pool Initialization
Pools come into existence when a PE registers the first instance of Pools come into existence when a PE registers the first instance of
the pool name. They disappear when the last PE deregisters. In the pool name with an ENRP server. They disappear when the last PE
other words, the starting of the first PE on some machine causes the deregisters. In other words, the starting of the first PE on some
creation of the pool when the registration reaches the ENRP server. machine causes the creation of the pool when the registration reaches
the ENRP server.
2.2. Pool Entity Registration 2.2. Pool Entity Registration
A new server joins an existing pool by sending a Registration message A new server joins an existing pool by sending a Registration message
in ASAP indicating the 'handle' of the pool that it wishes to join, a in ASAP to an ENRP server, indicating the 'handle' of the pool that
pool identifier for itself (chosen randomly) information about it's it wishes to join, a pool identifier for itself (chosen randomly)
lifetime in the pool, and what transport protocols and selection information about it's lifetime in the pool, and what transport
policies it supports. The Registration message is sent to its Home protocols and selection policies it supports. The ENRP server that
ENRP server. it first contacts is called its Home ENRP server, and maintains a
list of subscriptions by the PE as well as performing periodic audits
to confirm that the PE is still responsive.
Similar procedures are applied to de-register itself from the server Similar procedures are applied to de-register itself from the server
pool (or alternatively the server may simply let its previously state pool (or alternatively the server may simply let the lifetime that it
lifetime expire and be gracefully removed from the pool. previously registered with expire, after which it is gracefully
removed from the pool.
2.3. Pool Entity Selection 2.3. Pool Entity Selection
When an endpoint wishes to be connected to a server in the pool, this When an endpoint wishes to be connected to a server in the pool, it
requires the resolution of a server 'handle' to the IP addresses of a genereates a Handle Resolution message in ASAP and sends this to its
server or list of servers in the pool. This process may involve a home ENRP server. The ENRP server resolves the handle based on its
number of policies for server selection, for which the RSerPool knowledge of pool servers and returns a Handle Resolution Response in
protocol suite supports a few simply defined policies and allows the ASAP. The Resolution Response contains a list of the IP addresses of
use of external server selection input for more complex policies. one or more servers in the pool that can be contacted. The process
by which the list of servers is created may involve a number of
The endpoint generates a Handle Resolution message in ASAP and sends policies for server selection. The RSerPool protocol suite supports
this to its home ENRP server to start the resolution process. The a few simply defined policies and allows the use of external server
ENRP server resolves the handle based on its knowledge of pool selection input for more complex policies.
servers and returns a Handle Resolution Response in ASAP.
2.4. Endpoint Keepalive 2.4. Endpoint Keepalive
In order to maintain status information for members of the server ENRP servers monitor the status of pool elements using the ASAP Keep
pool, the ENRP server may audit the status of a particular pool Alive message. A Pool Element responds to the ASAP Keep Alive
element using an ASAP Keep Alive message. When received by the pool message with an Ack response.
element, it responds by verifying its membership in the pool in an
Ack message.
When a PE is found to be unreachable, for example, an endpoint In addition, an endpoint can notify its home ENRP server that the PE
conversing with the pool element finds that it can no longer be the endpoint was using has become unresponsive by sending the ENRP
reached by its transport connection, the endpoint can also inform its server an Endpoint Unreachable message.
home ENRP server by sending an Endpoint Unreachable message.
2.5. Failover Services 2.5. Failover Services
While maintaining application-independence, the RSerPool protocol While maintaining application-independence, the RSerPool protocol
suite provides some simple hooks for supporting failover of an suite provides some simple hooks for supporting failover of an
individual session with a pool element. Generally, mechanisms for individual session with a pool element. Generally, mechanisms for
failover that rely on application state or transaction status cannot failover that rely on application state or transaction status cannot
be supported without more specific knowledge of the application being be defined without more specific knowledge of the application being
supported. However, some simple mechanisms supported by RSerPool supported. However, some simple mechanisms supported by RSerPool
allow some level of failover that any application can use. allow some level of failover that any application can use.
2.5.1. Cookie Mechanism 2.5.1. Cookie Mechanism
Cookies may optionally be generated by the ASAP layer and Cookies may optionally be generated by the ASAP layer and
periodically sent from the PE to the PU. The PU only stores the last periodically sent from the PE to the PU. The PU only stores the last
received cookie. In case of fail over the PU sends this last received cookie. In case of fail over the PU sends this last
received cookie to the new PE. This method provides a simple way of received cookie to the new PE. This method provides a simple way of
state sharing between the PEs. Please note that the old PE should state sharing between the PEs. Please note that the old PE should
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2.5.2. Business Card Mechanism 2.5.2. Business Card Mechanism
A PE can send a business card to its peer (PE or PU) containing its A PE can send a business card to its peer (PE or PU) containing its
pool handle and guidance concerning which other PEs the peer should pool handle and guidance concerning which other PEs the peer should
use for failover. This gives a PE a means of telling a PU what it use for failover. This gives a PE a means of telling a PU what it
identifies as the "next best" PE to use in case of failure, which may identifies as the "next best" PE to use in case of failure, which may
be based on pool considerations, such as load balancing, or user be based on pool considerations, such as load balancing, or user
considerations, such as PEs that have the most up-to-date state considerations, such as PEs that have the most up-to-date state
information. information.
2.5.3. Failover Callback Mechanism 3. Endpoint Nameserver Redundancy Protocol (ENRP) Overview
TBD
3. ENRP
ENRP is used between ENRP servers in order to maintain a distributed, A server pool can be supported by one or more ENRP servers. If
fault-tolerant real-time registry service. ENRP servers communicate multiple ENRP servers are used to support a single pool then the ENRP
with each other in order to exchange information such as pool protocol is used between the ENRP servers in order to maintain a
membership changes, handlespace data synchronization, etc. distributed, fault-tolerant real-time registry service. ENRP servers
communicate with each other in order to exchange information such as
pool membership changes, handlespace data synchronization, etc.
3.1. Initialization 3.1. Initialization
Each ENRP server initially generates a 32-bit server ID that it uses Each ENRP server initially generates a 32-bit server ID that it uses
in subsequent messaging and remains unchanged over the lifetime of in subsequent messaging and remains unchanged over the lifetime of
the server. It then attempts to learn all of the other ENRP servers the server. It then attempts to learn all of the other ENRP servers
within the scope of the server pool, either using a pre-defined within the scope of the server pool, either by using a pre-defined
Mentor server or by sending out Presence messages on a well-known Mentor server or by sending out Presence messages on a well-known
multicast channel to determine other ENRP servers from the responses multicast channel to determine other ENRP servers from the responses
and select one as Mentor. and select one as Mentor. A Mentor can be any peer ENRP server that
it selects to provide current data about the pool.
It then requests the most current data about the pool handlespace It then requests the most current data about the pool handlespace
from its Mentor server and unpacks received Handle Table Response from its Mentor server and unpacks received Handle Table Response
messages into its local database. messages into its local database.
It is then ready to provide ENRP services. It is then ready to provide ENRP services.
3.2. Server Discovery 3.2. Server Discovery and Home Server Selection
PEs can now register their presence with the newly functioning ENRP PEs can now register their presence with the newly functioning ENRP
server by using ASAP messages. They discover the new ENRP server server by using ASAP messages. They discover the new ENRP server
after the server sends out an ASAP Server Announce message on the after the server sends out an ASAP Server Announce message on the
well-known ASAP multicast channel. well-known ASAP multicast channel. PEs need only register with one
ENRP server, as other ENRP servers supporting the pool will
synchronize their knowledge about pool elements using the ENRP
protocol.
The PE may have a configured list of ENRP servers to talk to, in The PE may have a configured list of ENRP servers to talk to, in the
which case it will start to setup associations with some number of form of a list of IP addresses, in which case it will start to setup
them and assign the first one that responds to it as its Home ENRP associations with some number of them and assign the first one that
Server. responds to it as its Home ENRP Server.
Alternatively it can listen on the multicast channel for a set period Alternatively it can listen on the multicast channel for a set period
and when it hears an ENRP server, start an association. The first and when it hears an ENRP server, start an association. The first
server it gets up can then become its Home ENRP Server. server it gets up can then become its Home ENRP Server.
3.3. Server Pool Maintenance 3.3. Server Pool Maintenance
PE failure detection, keepalive, etc. TBD PE failure detection, keepalive, etc. TBD
4. Example Scenarios 4. Example Scenarios
4.1. Example Scenario Using RSerPool Resolution Service 4.1. Example Scenario Using RSerPool Resolution Service
4.1.1. Standalone Mode
RSerPool can be used in a 'standalone' manner, where the application RSerPool can be used in a 'standalone' manner, where the application
uses RSerPool to determine the address of a primary server in the uses RSerPool to determine the address of a primary server in the
pool, and then interacts directly with that server without further pool, and then interacts directly with that server without further
use of RSerPool services. If the initial server fails, the use of RSerPool services. If the initial server fails, the
application uses RSerPool again to find the next server in the pool. application uses RSerPool again to find the next server in the pool.
4.1.2. Pool Mode
For pool user ("client") applications, if an ASAP implementation is For pool user ("client") applications, if an ASAP implementation is
available on the client system, there are typically only three available on the client system, there are typically only three
modifications required to the application source code: modifications required to the application source code:
1. Instead of specifying the hostnames of primary, secondary, 1. Instead of specifying the hostnames of primary, secondary,
tertiary servers, etc., the application user specifies a pool tertiary servers, etc., the application user specifies a pool
handle. handle.
2. Instead of using a DNS based service (e.g. the Unix library 2. Instead of using a DNS based service (e.g. the Unix library
function gethostbyname()) to translate from a hostname to an IP function gethostbyname()) to translate from a hostname to an IP
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2. The server should invoke the DEREGISTER service primitive to 2. The server should invoke the DEREGISTER service primitive to
remove itself from the server pool when shutting down. remove itself from the server pool when shutting down.
When using these RSerPool services, RSerPool provides benefits that When using these RSerPool services, RSerPool provides benefits that
are limited (as compared to utilizing all services), but nevertheless are limited (as compared to utilizing all services), but nevertheless
quite useful as compared to not using RSerPool at all. First, the quite useful as compared to not using RSerPool at all. First, the
client user need only supply a single string, i.e. the pool handle, client user need only supply a single string, i.e. the pool handle,
rather than a list of servers. Second, the decision as to which rather than a list of servers. Second, the decision as to which
server is to be used can be determined dynamically by the server server is to be used can be determined dynamically by the server
selection mechanism (i.e. a "pool policy" performed by ASAP; see ASAP selection mechanism (i.e. a "pool policy" performed by ASAP; see ASAP
[3]). Finally, when failures occur, these are reported to the pool [2]). Finally, when failures occur, these are reported to the pool
via signaling present in ASAP [3] and ENRP [4], other clients will via signaling present in ASAP [2] and ENRP [3], other clients will
eventually know (once this failure is confirmed by other elements of eventually know (once this failure is confirmed by other elements of
the RSerPool architecture) that this server has failed. the RSerPool architecture) that this server has failed.
4.2. Example Scenario Using RSerPool Session Services 4.2. Example Scenario Using RSerPool Session Services
When the full suite of RSerPool services are used, all communication When the full suite of RSerPool services are used, all communication
between the pool user and the pool element is mediated by the between the pool user and the pool element is mediated by the
RSerPool framework, including session establishment and teardown, and RSerPool framework, including session establishment and teardown, and
the sending and receiving of data. Accordingly, it is necessary to the sending and receiving of data. Accordingly, it is necessary to
modify the application to use the service primitives (i.e. the API) modify the application to use the service primitives (i.e. the API)
provided by RSerPool, rather than the transport layer primitives provided by RSerPool, rather than the transport layer primitives
provided by TCP, SCTP, or whatever transport protocol is being used. provided by TCP, SCTP, or whatever transport protocol is being used.
As in the previous case, sessions (rather than connections or As in the previous case, sessions (rather than connections or
associations) are established, and the destination endpoint is associations) are established, and the destination endpoint is
specified as a pool handle rather than as a list of IP addresses with specified as a pool handle rather than as a list of IP addresses with
a port number. However, failover from one pool element to another is a port number. However, failover from one pool element to another is
fully automatic, and can be transparent to the application: fully automatic, and can be transparent to the application (so long
as the application has saved enough state in a state cookie):
The RSerPool framework control channel provides maintainance The RSerPool framework control channel provides maintenance
functions to keep pool element lists, policies, etc. current. functions to keep pool element lists, policies, etc. current.
Since the application data (e.g. data channel) is managed by the Since the application data (e.g. data channel) is managed by the
RSerPool framework, unsent data (data not yet submitted by RSerPool framework, unsent data (data not yet submitted by
RSerPool to the underlying transport protocol) is automatically RSerPool to the underlying transport protocol) is automatically
redirected to the newly selected pool element upon failover. If redirected to the newly selected pool element upon failover. If
the underlying transport layer supports retrieval of unsent data the underlying transport layer supports retrieval of unsent data
(as in SCTP), retrieved unsent data can also be automatically re- (as in SCTP), retrieved unsent data can also be automatically re-
sent to the newly selected pool element. sent to the newly selected pool element.
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already documented in the ENRP and ASAP protocol specifications. already documented in the ENRP and ASAP protocol specifications.
6. IANA Considerations 6. IANA Considerations
This document does not require additional IANA actions beyond those This document does not require additional IANA actions beyond those
already identified in the ENRP and ASAP protocol specifications. already identified in the ENRP and ASAP protocol specifications.
7. Acknowledgements 7. Acknowledgements
The authors wish to thank Maureen Stillman, Qiaobing Xie, Randall The authors wish to thank Maureen Stillman, Qiaobing Xie, Randall
Stewart, and many others for their invaluable comments. Stewart, Scott Bradner, and many others for their invaluable
comments.
8. Normative References 8. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement [1] Tuexen, M., Xie, Q., Stewart, R., Shore, M., Ong, L., Loughney,
Levels", BCP 14, RFC 2119, March 1997.
[2] Tuexen, M., Xie, Q., Stewart, R., Shore, M., Ong, L., Loughney,
J., and M. Stillman, "Requirements for Reliable Server Pooling", J., and M. Stillman, "Requirements for Reliable Server Pooling",
RFC 3237, January 2002. RFC 3237, January 2002.
[3] Stewart, R., "Aggregate Server Access Protocol (ASAP)", [2] Stewart, R., "Aggregate Server Access Protocol (ASAP)",
draft-ietf-rserpool-asap-13 (work in progress), February 2006. draft-ietf-rserpool-asap-15 (work in progress), January 2007.
[4] Stewart, R., "Endpoint Handlespace Redundancy Protocol (ENRP)", [3] Stewart, R., "Endpoint Handlespace Redundancy Protocol (ENRP)",
draft-ietf-rserpool-enrp-13 (work in progress), February 2006. draft-ietf-rserpool-enrp-15 (work in progress), January 2007.
[5] Stewart, R., "Aggregate Server Access Protocol (ASAP) and [4] Stewart, R., "Aggregate Server Access Protocol (ASAP) and
Endpoint Handlespace Redundancy Protocol (ENRP) Parameters", Endpoint Handlespace Redundancy Protocol (ENRP) Parameters",
draft-ietf-rserpool-common-param-10 (work in progress), draft-ietf-rserpool-common-param-11 (work in progress),
February 2006. October 2006.
[6] Stillman, M., "Threats Introduced by Rserpool and Requirements [5] Stillman, M., "Threats Introduced by Rserpool and Requirements
for Security in response to Threats", for Security in response to Threats",
draft-ietf-rserpool-threats-05 (work in progress), July 2005. draft-ietf-rserpool-threats-06 (work in progress),
November 2006.
Authors' Addresses Authors' Addresses
Peter Lei Peter Lei
Cisco Systems, Inc. Cisco Systems, Inc.
955 Happfield Dr. 955 Happfield Dr.
Arlington Heights, IL 60004 Arlington Heights, IL 60004
US US
Phone: +1 773 695-8201 Phone: +1 773 695-8201
skipping to change at page 13, line 7 skipping to change at page 13, line 7
Michael Tuexen Michael Tuexen
Muenster Univ. of Applied Sciences Muenster Univ. of Applied Sciences
Stegerwaldstr. 39 Stegerwaldstr. 39
48565 Steinfurt 48565 Steinfurt
Germany Germany
Email: tuexen@fh-muenster.de Email: tuexen@fh-muenster.de
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