draft-ietf-ccamp-sdhsonet-control-01.txt | draft-ietf-ccamp-sdhsonet-control-02.txt | |||
---|---|---|---|---|
CCAMP G. Bernstein (Ciena) | ||||
Internet Draft E. Mannie (KPNQwest) | CCAMP Working Group G. Bernstein (Grotto Networking) | |||
Internet Draft E. Mannie (InterAir Link) | ||||
Document: <draft-ietf-ccamp-sdhsonet- V. Sharma (Metanoia, Inc.) | Document: <draft-ietf-ccamp-sdhsonet- V. Sharma (Metanoia, Inc.) | |||
control-01.txt> | control-02.txt> | |||
Category: Informational | Category: Informational | |||
Expires November 2002 May 2002 | Expires August 2003 February 2003 | |||
Framework for GMPLS-based Control of SDH/SONET Networks | Framework for GMPLS-based Control of SDH/SONET Networks | |||
<draft-ietf-ccamp-sdhsonet-control-01.txt> | <draft-ietf-ccamp-sdhsonet-control-02.txt> | |||
Status of this Memo | Status of this Memo | |||
This document is an Internet-Draft and is in full conformance with | This document is an Internet-Draft and is in full conformance with | |||
all provisions of Section 10 of RFC2026 [1]. | all provisions of Section 10 of RFC2026 [1]. | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF), its areas, and its working groups. Note that | Task Force (IETF), its areas, and its working groups. Note that | |||
other groups may also distribute working documents as Internet- | other groups may also distribute working documents as Internet- | |||
Drafts. Internet-Drafts are draft documents valid for a maximum of | Drafts. Internet-Drafts are draft documents valid for a maximum of | |||
skipping to change at line 53 | skipping to change at line 54 | |||
needed in transport path computation and network operations, | needed in transport path computation and network operations, | |||
together with the extensions to MPLS label distribution protocols | together with the extensions to MPLS label distribution protocols | |||
needed for the provisioning of transport circuits. New capabilities | needed for the provisioning of transport circuits. New capabilities | |||
that an MPLS control plane would bring to SONET/SDH networks, such | that an MPLS control plane would bring to SONET/SDH networks, such | |||
as new restoration methods and multi-layer circuit establishment, | as new restoration methods and multi-layer circuit establishment, | |||
are also discussed. | are also discussed. | |||
2. Conventions used in this document | 2. Conventions used in this document | |||
Bernstein, Mannie, Sharma Informational - November 2002 1 | Bernstein, Mannie, Sharma Informational - November 2002 1 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in | "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in | |||
this document are to be interpreted as described in RFC-2119 [2]. | this document are to be interpreted as described in RFC-2119 [2]. | |||
3. Introduction | 3. Introduction | |||
The CCAMP Working Group of the IETF is currently working on | The CCAMP Working Group of the IETF is currently working on | |||
extending MPLS [3] protocols to support multiple network layers and | extending MPLS [3] protocols to support multiple network layers and | |||
new services. This extended MPLS, which was initially known as | new services. This extended MPLS, which was initially known as | |||
skipping to change at line 106 | skipping to change at line 107 | |||
3.1. MPLS Overview | 3.1. MPLS Overview | |||
A major advantage of the MPLS architecture [3] for use as a general | A major advantage of the MPLS architecture [3] for use as a general | |||
network control plane is its clear separation between the forwarding | network control plane is its clear separation between the forwarding | |||
(or data) plane, the signaling (or connection control) plane, and | (or data) plane, the signaling (or connection control) plane, and | |||
the routing (or topology discovery/resource status) plane. This | the routing (or topology discovery/resource status) plane. This | |||
allows the work on MPLS extensions to focus on the forwarding and | allows the work on MPLS extensions to focus on the forwarding and | |||
signaling planes, while allowing well-known IP routing protocols to | signaling planes, while allowing well-known IP routing protocols to | |||
be reused in the routing plane. This clear separation also allows | be reused in the routing plane. This clear separation also allows | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 2 | Bernstein, Mannie, Sharma Expires August 2003 2 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
for MPLS to be used to control networks that do not have a packet- | for MPLS to be used to control networks that do not have a packet- | |||
based forwarding plane. | based forwarding plane. | |||
An MPLS network consists of MPLS nodes called Label Switch Routers | An MPLS network consists of MPLS nodes called Label Switch Routers | |||
(LSRs) connected via circuits called Label Switched Paths (LSPs). An | (LSRs) connected via circuits called Label Switched Paths (LSPs). An | |||
LSP is unidirectional and could be of several different types such | LSP is unidirectional and could be of several different types such | |||
as point-to-point, point-to-multipoint, and multipoint-to-point. | as point-to-point, point-to-multipoint, and multipoint-to-point. | |||
Border LSRs in an MPLS network act either as ingress or egress LSRs | Border LSRs in an MPLS network act either as ingress or egress LSRs | |||
depending on the direction of the traffic being forwarded. | depending on the direction of the traffic being forwarded. | |||
skipping to change at line 163 | skipping to change at line 164 | |||
appropriate forwarding, such as normal IP forwarding. We will see | appropriate forwarding, such as normal IP forwarding. We will see | |||
that for a SONET/SDH network these operations do not occur in quite | that for a SONET/SDH network these operations do not occur in quite | |||
the same way. | the same way. | |||
3.2. SDH/SONET Overview | 3.2. SDH/SONET Overview | |||
There are currently two different multiplexing technologies in use | There are currently two different multiplexing technologies in use | |||
in optical networks: wavelength division multiplexing (WDM) and time | in optical networks: wavelength division multiplexing (WDM) and time | |||
division multiplexing (TDM). This work focuses on TDM technology. | division multiplexing (TDM). This work focuses on TDM technology. | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 3 | Bernstein, Mannie, Sharma Expires August 2003 3 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
SDH and SONET are two TDM standards widely used by operators to | SDH and SONET are two TDM standards widely used by operators to | |||
transport and multiplex different tributary signals over optical | transport and multiplex different tributary signals over optical | |||
links, thus creating a multiplexing structure, which we call the | links, thus creating a multiplexing structure, which we call the | |||
SDH/SONET multiplex. SDH, which was developed by the ETSI and later | SDH/SONET multiplex. SDH, which was developed by the ETSI and later | |||
standardized by the ITU-T [4], is now used worldwide, while SONET, | standardized by the ITU-T [4], is now used worldwide, while SONET, | |||
which was standardized by the ANSI [5], is mainly used in the US. | which was standardized by the ANSI [5], is mainly used in the US. | |||
However, these two standards have several similarities, and to some | However, these two standards have several similarities, and to some | |||
extent SONET can be viewed as a subset of SDH. Internetworking | extent SONET can be viewed as a subset of SDH. Internetworking | |||
between the two is possible using gateways. | between the two is possible using gateways. | |||
skipping to change at line 218 | skipping to change at line 219 | |||
xN x1 | xN x1 | |||
STM-N<----AUG<----AU-4<--VC4<------------------------------C-4 E4 | STM-N<----AUG<----AU-4<--VC4<------------------------------C-4 E4 | |||
^ ^ | ^ ^ | |||
Ix3 Ix3 | Ix3 Ix3 | |||
I I x1 | I I x1 | |||
I -----TUG-3<----TU-3<---VC-3<---I | I -----TUG-3<----TU-3<---VC-3<---I | |||
I ^ C-3 DS3/E3 | I ^ C-3 DS3/E3 | |||
-------AU-3<---VC-3<-- I ---------------------I | -------AU-3<---VC-3<-- I ---------------------I | |||
^ I | ^ I | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 4 | Bernstein, Mannie, Sharma Expires August 2003 4 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
Ix7 Ix7 | Ix7 Ix7 | |||
I I x1 | I I x1 | |||
-----TUG-2<---TU-2<---VC-2<---C-2 DS2/T2 | -----TUG-2<---TU-2<---VC-2<---C-2 DS2/T2 | |||
^ ^ | ^ ^ | |||
I I x3 | I I x3 | |||
I I----TU-12<---VC-12<--C-12 E1 | I I----TU-12<---VC-12<--C-12 E1 | |||
I | I | |||
I x4 | I x4 | |||
I-------TU-11<---VC-11<--C-11 DS1/T1 | I-------TU-11<---VC-11<--C-11 DS1/T1 | |||
skipping to change at line 271 | skipping to change at line 272 | |||
be re-aligned via a pointer, i.e. a VC-x in the case of SDH and a | be re-aligned via a pointer, i.e. a VC-x in the case of SDH and a | |||
SPE in the case of SONET. | SPE in the case of SONET. | |||
An STM-N/STS-N signal is formed from N x STM-1/STS-1 signals via | An STM-N/STS-N signal is formed from N x STM-1/STS-1 signals via | |||
byte interleaving. The VCs/SPEs in the N interleaved frames are | byte interleaving. The VCs/SPEs in the N interleaved frames are | |||
independent and float according to their own clocking. To transport | independent and float according to their own clocking. To transport | |||
tributary signals in excess of the basic STM-1/STS-1 signal rates, | tributary signals in excess of the basic STM-1/STS-1 signal rates, | |||
the VCs/SPEs can be concatenated, i.e., glued together. In this case | the VCs/SPEs can be concatenated, i.e., glued together. In this case | |||
their relationship with respect to each other is fixed in time and | their relationship with respect to each other is fixed in time and | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 5 | Bernstein, Mannie, Sharma Expires August 2003 5 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
hence this relieves, when possible, an end system of any inverse | hence this relieves, when possible, an end system of any inverse | |||
multiplexing bonding processes. Different types of concatenations | multiplexing bonding processes. Different types of concatenations | |||
are defined in SDH/SONET. | are defined in SDH/SONET. | |||
For example, standard SONET concatenation allows the concatenation | For example, standard SONET concatenation allows the concatenation | |||
of M x STS-1 signals within an STS-N signal with M <= N, and M = 3, | of M x STS-1 signals within an STS-N signal with M <= N, and M = 3, | |||
12, 48, 192,...). The SPEs of these M x STS-1s can be concatenated | 12, 48, 192,...). The SPEs of these M x STS-1s can be concatenated | |||
to form an STS-Mc. The STS-Mc notation is short hand for describing | to form an STS-Mc. The STS-Mc notation is short hand for describing | |||
an STS-M signal whose SPEs have been concatenated. | an STS-M signal whose SPEs have been concatenated. | |||
skipping to change at line 327 | skipping to change at line 328 | |||
client is in a different time zone than the operator's main office. | client is in a different time zone than the operator's main office. | |||
This first-time connection time is frequently accounted for in the | This first-time connection time is frequently accounted for in the | |||
overall establishment time. | overall establishment time. | |||
3.3.3. Planning Tool Operation | 3.3.3. Planning Tool Operation | |||
Another portion of the time is consumed by planning tools that run | Another portion of the time is consumed by planning tools that run | |||
simulations using heuristic algorithms to find an optimized | simulations using heuristic algorithms to find an optimized | |||
placement for the required circuits. These planning tools can | placement for the required circuits. These planning tools can | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 6 | Bernstein, Mannie, Sharma Expires August 2003 6 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
require a significant running time, sometimes on the order of days. | require a significant running time, sometimes on the order of days. | |||
These simulations are, in general, executed for a set of demands for | These simulations are, in general, executed for a set of demands for | |||
circuits, i.e., a batch mode, to improve the optimality of network | circuits, i.e., a batch mode, to improve the optimality of network | |||
resource usage and other parameters. Today, we do not really have a | resource usage and other parameters. Today, we do not really have a | |||
means to reduce this simulation time. On the contrary, to support | means to reduce this simulation time. On the contrary, to support | |||
fast, on-line, circuit establishment, this phase may be invoked more | fast, on-line, circuit establishment, this phase may be invoked more | |||
frequently, i.e., we will not "batch up" as many connection | frequently, i.e., we will not "batch up" as many connection | |||
requests before we plan out the corresponding circuits. This means | requests before we plan out the corresponding circuits. This means | |||
that the network may need to be re-optimized periodically, implying | that the network may need to be re-optimized periodically, implying | |||
skipping to change at line 384 | skipping to change at line 385 | |||
networks does not preclude either model, although MPLS is itself a | networks does not preclude either model, although MPLS is itself a | |||
distributed technology. | distributed technology. | |||
The basic tradeoff between the centralized and distributed | The basic tradeoff between the centralized and distributed | |||
approaches is that of complexity of the network elements versus that | approaches is that of complexity of the network elements versus that | |||
of the network management system (NMS). Since adding functionality | of the network management system (NMS). Since adding functionality | |||
to existing SDH/SONET network elements may not be possible, a | to existing SDH/SONET network elements may not be possible, a | |||
centralized approach may be needed in some cases. The main issue | centralized approach may be needed in some cases. The main issue | |||
facing centralized control via an NMS is one of scalability. For | facing centralized control via an NMS is one of scalability. For | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 7 | Bernstein, Mannie, Sharma Expires August 2003 7 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
instance, this approach may be limited in the number of network | instance, this approach may be limited in the number of network | |||
elements that can be managed (e.g., one thousand). It is, therefore, | elements that can be managed (e.g., one thousand). It is, therefore, | |||
quite common for operators to deploy several NMSÆs in parallel at | quite common for operators to deploy several NMSÆs in parallel at | |||
the Network Management Layer, each managing a different zone. In | the Network Management Layer, each managing a different zone. In | |||
that case, however, a Service Management Layer must be built on the | that case, however, a Service Management Layer must be built on the | |||
top of several individual NMSÆs to take care of end-to-end on-demand | top of several individual NMSÆs to take care of end-to-end on-demand | |||
services. On the other hand, in a complex and/or dense network, | services. On the other hand, in a complex and/or dense network, | |||
restoration could be faster with a distributed approach than with a | restoration could be faster with a distributed approach than with a | |||
centralized approach. | centralized approach. | |||
Let's now look at how the major control plane functional components | Let's now look at how the major control plane functional components | |||
are handled via the centralized and distributed approaches: | are handled via the centralized and distributed approaches: | |||
3.4.1. Topology Discovery and Resource Dissemination | 3.4.1. Topology Discovery and Resource Dissemination | |||
Currently NMS's maintain a consistent view of all the networking | Currently NMS's maintain a consistent view of all the networking | |||
layers under their purview. This can include the physical topology, | layers under their purview. This can include the physical topology, | |||
such as information about fibers and ducts. Since most of this | such as information about fibers and ducts. Since most of this | |||
information is entered manually, it remains error prone. | information is entered manually, it remains error prone. | |||
A link state GMPLS routing protocol, on the other hand, could | A link state GMPLS routing protocol, on the other hand, could perform | |||
perform automatic topology discovery and dissemination the topology | automatic topology discovery and dissemination the topology as well as | |||
as well as resource status. This information would be available to | resource status. This information would be available to all nodes in | |||
all nodes in the network, and hence also the NMS. Hence one can | the network, and hence also the NMS. Hence one can look at a continuum | |||
look at a continuum of functionality between manually provisioned | of functionality between manually provisioned topology information (of | |||
topology information (of which there will always be some) and fully | which there will always be some) and fully automated discovery and | |||
automated discovery and dissemination as in a link state protocol. | dissemination as in a link state protocol. Note that, unlike the IP | |||
Note that, unlike the IP datagram case, a link state routing | datagram case, a link state routing protocol applied to the SDH/SONET | |||
protocol applied to the SDH/SONET network does not have any service | network does not have any service impacting implications. This is | |||
impacting implications. This is because in the SDH/SONET case, the | because in the SDH/SONET case, the circuit is source-routed (so there | |||
circuit is source-routed (so there can be no loops), and no traffic | can be no loops), and no traffic is transmitted until a circuit has | |||
is transmitted until a circuit has been established, and an | been established, and an acknowledgement received at the source. | |||
acknowledgement received at the source. | ||||
3.4.2. Path Computation (Route Determination) | 3.4.2. Path Computation (Route Determination) | |||
In the SDH/SONET case, unlike the IP datagram case, there is no need | In the SDH/SONET case, unlike the IP datagram case, there is no need | |||
for network elements to all perform the same path calculation [9]. | for network elements to all perform the same path calculation [9]. | |||
In addition, path determination is an area for vendors to provide a | In addition, path determination is an area for vendors to provide a | |||
potentially significant value addition in terms of network | potentially significant value addition in terms of network | |||
efficiency, reliability, and service differentiation. In this sense, | efficiency, reliability, and service differentiation. In this sense, | |||
a centralized approach to path computation may be easier to operate | a centralized approach to path computation may be easier to operate | |||
and upgrade. For example, new features such as new types of path | and upgrade. For example, new features such as new types of path | |||
diversity or new optimization algorithms can be introduced with a | diversity or new optimization algorithms can be introduced with a | |||
simple NMS software upgrade. On the other hand, updating switches | simple NMS software upgrade. On the other hand, updating switches | |||
with new path computation software is a more complicated task. In | with new path computation software is a more complicated task. In | |||
addition, many of the algorithms can be fairly computationally | addition, many of the algorithms can be fairly computationally | |||
intensive and may be completely unsuitable for the embedded | intensive and may be completely unsuitable for the embedded | |||
processing environment available on most switches. In restoration | processing environment available on most switches. In restoration | |||
scenarios, the ability to perform a reasonably sophisticated level | scenarios, the ability to perform a reasonably sophisticated level | |||
of path computation on the network element can be particularly | of path computation on the network element can be particularly | |||
useful for restoring traffic during major network faults. | useful for restoring traffic during major network faults. | |||
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3.4.3. Connection Establishment (provisioning) | 3.4.3. Connection Establishment (provisioning) | |||
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The actual setting up of circuits, i.e., a coupled collection of | The actual setting up of circuits, i.e., a coupled collection of | |||
cross connects across a network, can be done either via the NMS | cross connects across a network, can be done either via the NMS | |||
setting up individual cross connects or via a "soft permanent LSP" | setting up individual cross connects or via a "soft permanent LSP" | |||
(SPLSP) type approach. In the SPLSP approach, the NMS may just kick | (SPLSP) type approach. In the SPLSP approach, the NMS may just kick | |||
off the connection at the "ingress" switch with GMPLS signaling | off the connection at the "ingress" switch with GMPLS signaling | |||
setting up the connection from that point onward. Connection | setting up the connection from that point onward. Connection | |||
establishment is the trickiest part to distribute, however, since | establishment is the trickiest part to distribute, however, since | |||
errors in the connection setup/tear down process are service | errors in the connection setup/tear down process are service | |||
impacting. | impacting. | |||
skipping to change at line 496 | skipping to change at line 496 | |||
Suitable for very dynamic For less dynamic demands | Suitable for very dynamic For less dynamic demands | |||
demands (longer lived) | demands (longer lived) | |||
Probably faster to restore, Probably slower to restore,but | Probably faster to restore, Probably slower to restore,but | |||
but more difficult to have could effect reliable | but more difficult to have could effect reliable | |||
reliable restoration. restoration. | reliable restoration. restoration. | |||
High scalability Limited scalability: #nodes, | High scalability Limited scalability: #nodes, | |||
(hierarchical) links, circuits, messages | (hierarchical) links, circuits, messages | |||
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Planning (optimization) Planning is a background | Planning (optimization) Planning is a background | |||
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harder to achieve centralized activity | harder to achieve centralized activity | |||
Easier future integration | Easier future integration | |||
with other control plane | with other control plane | |||
layers | layers | |||
Table 1. Qualitative comparison between centralized and distributed | Table 1. Qualitative comparison between centralized and distributed | |||
approaches. | approaches. | |||
3.5. Why SDH/SONET will not Disappear Tomorrow | 3.5. Why SDH/SONET will not Disappear Tomorrow | |||
skipping to change at line 550 | skipping to change at line 551 | |||
directly over a wavelength. A framing or encapsulation is always | directly over a wavelength. A framing or encapsulation is always | |||
required to delimit IP datagrams. The Total Length field of an IP | required to delimit IP datagrams. The Total Length field of an IP | |||
header cannot be trusted to find the start of a new datagram, since | header cannot be trusted to find the start of a new datagram, since | |||
it could be corrupted and would result in a loss of synchronization. | it could be corrupted and would result in a loss of synchronization. | |||
The typical framing used today for IP over DWDM is defined in | The typical framing used today for IP over DWDM is defined in | |||
RFC1619/RFC2615 and known as POS (Packet Over SONET/SDH), i.e., IP | RFC1619/RFC2615 and known as POS (Packet Over SONET/SDH), i.e., IP | |||
over PPP (in HDLC-like format) over SDH/SONET. SDH and SONET are | over PPP (in HDLC-like format) over SDH/SONET. SDH and SONET are | |||
actually efficient encapsulations for IP. For instance, with an | actually efficient encapsulations for IP. For instance, with an | |||
average IP datagram length of 350 octets, an IP over GBE | average IP datagram length of 350 octets, an IP over GBE | |||
encapsulation using an 8B/10B encoding results in 28% overhead, an | encapsulation using an 8B/10B encoding results in 28% overhead, an | |||
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IP/ATM/SDH encapsulation results in 22% overhead and an IP/PPP/SDH | IP/ATM/SDH encapsulation results in 22% overhead and an IP/PPP/SDH | |||
encapsulation results in only 6% overhead. (New simplified | encapsulation results in only 6% overhead. (New simplified | |||
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encapsulations could reduce this overhead to as low as 3%, but the | encapsulations could reduce this overhead to as low as 3%, but the | |||
gain is not huge compared to SDH and SONET, which have other | gain is not huge compared to SDH and SONET, which have other | |||
benefits as well.) | benefits as well.) | |||
Any encapsulation of IP over WDM should at least provide error | Any encapsulation of IP over WDM should at least provide error | |||
monitoring capabilities (to detect signal degradation), error | monitoring capabilities (to detect signal degradation), error | |||
correction capabilities, such as FEC (Forward Error Correction) that | correction capabilities, such as FEC (Forward Error Correction) that | |||
are particularly needed for ultra long haul transmission, sufficient | are particularly needed for ultra long haul transmission, sufficient | |||
timing information, to allow robust synchronization (that is, to | timing information, to allow robust synchronization (that is, to | |||
detect the beginning of a packet), and capacity to transport | detect the beginning of a packet), and capacity to transport | |||
skipping to change at line 606 | skipping to change at line 607 | |||
that contains them, namely the STS-1, VT-6, VT-3, VT-2 and VT-1.5. | that contains them, namely the STS-1, VT-6, VT-3, VT-2 and VT-1.5. | |||
The STS-1 SPE corresponds to a VC-3, a VT-6 SPE corresponds to a VC- | The STS-1 SPE corresponds to a VC-3, a VT-6 SPE corresponds to a VC- | |||
2, a VT-2 SPE corresponds to a VC-12, and a VT-1.5 SPE corresponds | 2, a VT-2 SPE corresponds to a VC-12, and a VT-1.5 SPE corresponds | |||
to a VC-11. The SONET VT-3 SPE has no correspondence in SDH, however | to a VC-11. The SONET VT-3 SPE has no correspondence in SDH, however | |||
SDH's VC-4 corresponds to SONET's STS-3c SPE. | SDH's VC-4 corresponds to SONET's STS-3c SPE. | |||
In addition, it is possible to concatenate some of the structures | In addition, it is possible to concatenate some of the structures | |||
that contain these elements to build larger elements. For instance, | that contain these elements to build larger elements. For instance, | |||
SDH allows the concatenation of X contiguous AU-4s to build a VC-4- | SDH allows the concatenation of X contiguous AU-4s to build a VC-4- | |||
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Xc and of m contiguous TU-2s to build a VC-2-mc. In that case, a VC- | Xc and of m contiguous TU-2s to build a VC-2-mc. In that case, a VC- | |||
4-Xc or a VC-2-mc can be switched and controlled by MPLS. Note that | 4-Xc or a VC-2-mc can be switched and controlled by MPLS. Note that | |||
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SDH also defines virtual (non-contiguous) concatenation of TU- 2s, | SDH also defines virtual (non-contiguous) concatenation of TU- 2s, | |||
but in that case each constituent VC-2 is switched individually. | but in that case each constituent VC-2 is switched individually. | |||
4.2. SDH/SONET LSR and LSP Terminology | 4.2. SDH/SONET LSR and LSP Terminology | |||
Let a SDH or SONET Terminal Multiplexer (TM), Add-Drop Multiplexer | Let a SDH or SONET Terminal Multiplexer (TM), Add-Drop Multiplexer | |||
(ADM) or cross-connect (i.e. a switch) be called an SDH/SONET LSR. A | (ADM) or cross-connect (i.e. a switch) be called an SDH/SONET LSR. A | |||
SDH/SONET path or circuit between two SDH/SONET LSRs now becomes a | SDH/SONET path or circuit between two SDH/SONET LSRs now becomes a | |||
GMPLS LSP. An SDH/SONET LSP is a logical connection between the | GMPLS LSP. An SDH/SONET LSP is a logical connection between the | |||
point at which a tributary signal (client layer) is adapted into its | point at which a tributary signal (client layer) is adapted into its | |||
skipping to change at line 663 | skipping to change at line 664 | |||
protected versus being routed over those that are not ring protected | protected versus being routed over those that are not ring protected | |||
(differentiation based on reliability), the type of protection on a | (differentiation based on reliability), the type of protection on a | |||
SDH/SONET line would be an important topological parameter that | SDH/SONET line would be an important topological parameter that | |||
would have to be distributed via the link state routing protocol. | would have to be distributed via the link state routing protocol. | |||
(ii) Information that is only needed between two "adjacent" switches | (ii) Information that is only needed between two "adjacent" switches | |||
for the purposes of connection establishment is appropriate for | for the purposes of connection establishment is appropriate for | |||
distribution via one of the label distribution protocols. In fact, | distribution via one of the label distribution protocols. In fact, | |||
this information can be thought of as the "virtual" label. For | this information can be thought of as the "virtual" label. For | |||
example, in SONET networks, when distributing information to | example, in SONET networks, when distributing information to | |||
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switches concerning an end-to-end STS-1 path traversing a network, | switches concerning an end-to-end STS-1 path traversing a network, | |||
it is critical that adjacent switches agree on the multiplex entry | it is critical that adjacent switches agree on the multiplex entry | |||
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used by this STS-1 (but this information is only of local | used by this STS-1 (but this information is only of local | |||
significance between those two switches). Hence, the multiplex entry | significance between those two switches). Hence, the multiplex entry | |||
number in this case can be used as a virtual label. Note that the | number in this case can be used as a virtual label. Note that the | |||
label is virtual, in that it is not appended to the payload in any | label is virtual, in that it is not appended to the payload in any | |||
way, but it is still a label in the sense that it uniquely | way, but it is still a label in the sense that it uniquely | |||
identifies the signal locally on the link between the two switches. | identifies the signal locally on the link between the two switches. | |||
(iii) Information that all switches in the path need to know about a | (iii) Information that all switches in the path need to know about a | |||
circuit will also be distributed via the label distribution | circuit will also be distributed via the label distribution | |||
protocol. Examples of such information include bandwidth, priority, | protocol. Examples of such information include bandwidth, priority, | |||
skipping to change at line 720 | skipping to change at line 721 | |||
compare and contrast this situation with the datagram routing case | compare and contrast this situation with the datagram routing case | |||
[15]. In the case of routing datagrams, all routes on all nodes | [15]. In the case of routing datagrams, all routes on all nodes | |||
must be calculated exactly the same to avoid loops and "black | must be calculated exactly the same to avoid loops and "black | |||
holes". In circuit switching, this is not the case since routes are | holes". In circuit switching, this is not the case since routes are | |||
established per circuit and are fixed for that circuit. Hence, | established per circuit and are fixed for that circuit. Hence, | |||
unlike the datagram case, routing is not service impacting in the | unlike the datagram case, routing is not service impacting in the | |||
circuit switched case. This is helpful, because, to accommodate the | circuit switched case. This is helpful, because, to accommodate the | |||
optical layer, routing protocols need to be supplemented with new | optical layer, routing protocols need to be supplemented with new | |||
information, much more than the datagram case. This information is | information, much more than the datagram case. This information is | |||
also likely to be used in different ways for implementing different | also likely to be used in different ways for implementing different | |||
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user services. Due to the increase in information transferred in | user services. Due to the increase in information transferred in | |||
the routing protocol, it may be useful to separate the relatively | the routing protocol, it may be useful to separate the relatively | |||
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static parameters concerning a link from those that may be subject | static parameters concerning a link from those that may be subject | |||
to frequent changes. The current GMPLS routing extensions | to frequent changes. The current GMPLS routing extensions | |||
[12],[13],[14] do not make such a separation, however. | [12],[13],[14] do not make such a separation, however. | |||
6.1. Switching Capabilities | 6.1. Switching Capabilities | |||
The main switching capabilities that characterize a SONET/SDH end | The main switching capabilities that characterize a SONET/SDH end | |||
system and thus need to be advertised via the link state routing | system and thus need to be advertised via the link state routing | |||
protocol are: the switching granularity, supported forms of | protocol are: the switching granularity, supported forms of | |||
concatenation, and the level of transparency. | concatenation, and the level of transparency. | |||
skipping to change at line 776 | skipping to change at line 777 | |||
VC-12s. In order to cover the needs of all manufacturers and | VC-12s. In order to cover the needs of all manufacturers and | |||
operators, GMPLS signaling [6],[7],[8] covers both higher order and | operators, GMPLS signaling [6],[7],[8] covers both higher order and | |||
lower order signals. | lower order signals. | |||
6.1.2. Signal Concatenation Capabilities | 6.1.2. Signal Concatenation Capabilities | |||
As stated in the SONET/SDH overview, to transport tributary signals | As stated in the SONET/SDH overview, to transport tributary signals | |||
with rates in excess of the basic STM-1/STS-1 signal, the VCs/SPEs | with rates in excess of the basic STM-1/STS-1 signal, the VCs/SPEs | |||
can be concatenated, i.e., glued together. Different types of | can be concatenated, i.e., glued together. Different types of | |||
concatenations are defined: contiguous standard concatenation, | concatenations are defined: contiguous standard concatenation, | |||
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arbitrary concatenation, and virtual concatenation with different | arbitrary concatenation, and virtual concatenation with different | |||
rules concerning their size, placement, and binding. | rules concerning their size, placement, and binding. | |||
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Standard SONET concatenation allows the concatenation of M x STS-1 | Standard SONET concatenation allows the concatenation of M x STS-1 | |||
signals within an STS-N signal with M <= N, and M = 3, 12, 48, 192, | signals within an STS-N signal with M <= N, and M = 3, 12, 48, 192, | |||
...). The SPEs of these M x STS-1s can be concatenated to form an | ...). The SPEs of these M x STS-1s can be concatenated to form an | |||
STS-Mc. The STS-Mc notation is short hand for describing an STS-M | STS-Mc. The STS-Mc notation is short hand for describing an STS-M | |||
signal whose SPEs have been concatenated. The multiplexing | signal whose SPEs have been concatenated. The multiplexing | |||
procedures for SDH and SONET are given in references [4] and [5], | procedures for SDH and SONET are given in references [4] and [5], | |||
respectively. Constraints are imposed on the size of STS-Mc signals, | respectively. Constraints are imposed on the size of STS-Mc signals, | |||
i.e., they must be a multiple of 3, and on their starting location | i.e., they must be a multiple of 3, and on their starting location | |||
and interleaving. | and interleaving. | |||
skipping to change at line 833 | skipping to change at line 833 | |||
implement with SONET/SDH signals rather than packets. Since virtual | implement with SONET/SDH signals rather than packets. Since virtual | |||
concatenation is provided by end systems, it is compatible with | concatenation is provided by end systems, it is compatible with | |||
existing SONET/SDH networks. Virtual concatenation is defined for | existing SONET/SDH networks. Virtual concatenation is defined for | |||
both higher order signals and low order signals. Table 3 shows the | both higher order signals and low order signals. Table 3 shows the | |||
nomenclature and capacity for several lower-order virtually | nomenclature and capacity for several lower-order virtually | |||
concatenated signals contained within different higher-order | concatenated signals contained within different higher-order | |||
signals. | signals. | |||
Table 3 Capacity of Virtually Concatenated VTn-Xv (9/G.707) | Table 3 Capacity of Virtually Concatenated VTn-Xv (9/G.707) | |||
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Carried In X Capacity In steps | Carried In X Capacity In steps | |||
of | of | |||
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VT1.5/ STS-1/VC-3 1 to 28 1600kbit/s to 1600kbit/s | VT1.5/ STS-1/VC-3 1 to 28 1600kbit/s to 1600kbit/s | |||
VC-11-Xv 44800kbit/s | VC-11-Xv 44800kbit/s | |||
VT2/ STS-1/VC-3 1 to 21 2176kbit/s to 2176kbit/s | VT2/ STS-1/VC-3 1 to 21 2176kbit/s to 2176kbit/s | |||
VC-12-Xv 45696kbit/s | VC-12-Xv 45696kbit/s | |||
VT1.5/ STS-3c/VC-4 1 to 64 1600kbit/s to 1600kbit/s | VT1.5/ STS-3c/VC-4 1 to 64 1600kbit/s to 1600kbit/s | |||
VC-11-Xv 102400kbit/s | VC-11-Xv 102400kbit/s | |||
VT2/ STS-3c/VC-4 1 to 63 2176kbit/s to 2176kbit/s | VT2/ STS-3c/VC-4 1 to 63 2176kbit/s to 2176kbit/s | |||
skipping to change at line 888 | skipping to change at line 888 | |||
viewed as a constraint, since some multiplexers and switches may not | viewed as a constraint, since some multiplexers and switches may not | |||
switch with as fine a granularity as others. Table 4 summarizes the | switch with as fine a granularity as others. Table 4 summarizes the | |||
levels of SONET/SDH transparency. | levels of SONET/SDH transparency. | |||
Table 4. SONET/SDH transparency types and their properties. | Table 4. SONET/SDH transparency types and their properties. | |||
Transparency Type Comments | Transparency Type Comments | |||
Path Layer (or Line Standard higher order SONET path | Path Layer (or Line Standard higher order SONET path | |||
Terminating) switching. Line overhead is terminated | Terminating) switching. Line overhead is terminated | |||
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or modified. | or modified. | |||
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Line Level (or Section Preserves line overhead and switches | Line Level (or Section Preserves line overhead and switches | |||
Terminating) the entire line multiplex as a whole. | Terminating) the entire line multiplex as a whole. | |||
Section overhead is terminated or | Section overhead is terminated or | |||
modified. | modified. | |||
Section layer Preserves all section overhead, | Section layer Preserves all section overhead, | |||
Basically does not touch any of the | Basically does not touch any of the | |||
SONET/SDH bits. | SONET/SDH bits. | |||
6.2. Protection | 6.2. Protection | |||
skipping to change at line 945 | skipping to change at line 944 | |||
1:1 Yes Dedicated protection. | 1:1 Yes Dedicated protection. | |||
1:N Yes One Protection line shared | 1:N Yes One Protection line shared | |||
by N working lines | by N working lines | |||
4F-BLSR (4 Yes Dedicated protection, with | 4F-BLSR (4 Yes Dedicated protection, with | |||
fiber bi- alternative ring path. | fiber bi- alternative ring path. | |||
directional | directional | |||
line switched | line switched | |||
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ring) | ring) | |||
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2F-BLSR (2 Yes Dedicated protection, with | 2F-BLSR (2 Yes Dedicated protection, with | |||
fiber bi- alternative ring path | fiber bi- alternative ring path | |||
directional | directional | |||
line switched | line switched | |||
ring) | ring) | |||
UPSR (uni- No Dedicated protection via | UPSR (uni- No Dedicated protection via | |||
directional alternative ring path. | directional alternative ring path. | |||
path switched Typically used in access | path switched Typically used in access | |||
ring) networks. | ring) networks. | |||
skipping to change at line 999 | skipping to change at line 997 | |||
number between working and protection lines | number between working and protection lines | |||
Protection line Used to indicate if the line is a | Protection line Used to indicate if the line is a | |||
number protection line. | number protection line. | |||
Extra Traffic Yes or No | Extra Traffic Yes or No | |||
Supported | Supported | |||
Layer If this protection parameter is specific to | Layer If this protection parameter is specific to | |||
SONET then this parameter is unneeded, | SONET then this parameter is unneeded, | |||
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otherwise it would indicate the signal | otherwise it would indicate the signal | |||
layer that the protection is applied. | layer that the protection is applied. | |||
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An open issue concerning protection is the extent of information | An open issue concerning protection is the extent of information | |||
regarding protection that must be disseminated. The contents of | regarding protection that must be disseminated. The contents of | |||
Table 6 represent one extreme while a simple enumerated list of: | Table 6 represent one extreme while a simple enumerated list of: | |||
Extra-Traffic/Protection line, Unprotected, Shared (1:N)/Working | Extra-Traffic/Protection line, Unprotected, Shared (1:N)/Working | |||
line, Dedicated (1:1, 1+1)/Working Line, Enhanced (Ring) /Working | line, Dedicated (1:1, 1+1)/Working Line, Enhanced (Ring) /Working | |||
Line, represents the other. | Line, represents the other. | |||
There is also a potential implication for link bundling [16], that | There is also a potential implication for link bundling [16], that | |||
is, for each link, the routing protocol could advertise whether that | is, for each link, the routing protocol could advertise whether that | |||
link is a working or protection link and possibly some parameters | link is a working or protection link and possibly some parameters | |||
skipping to change at line 1055 | skipping to change at line 1052 | |||
information is updated, the percentage of connection establishments | information is updated, the percentage of connection establishments | |||
that are unsuccessful on their first attempt due to the granularity | that are unsuccessful on their first attempt due to the granularity | |||
of the advertised information, and the extent to which network | of the advertised information, and the extent to which network | |||
resources can be optimized. There are different levels of | resources can be optimized. There are different levels of | |||
summarization that are being considered today for the available | summarization that are being considered today for the available | |||
capacity information. At one extreme, all signals that are allocated | capacity information. At one extreme, all signals that are allocated | |||
on an interface could be advertised, while at the other extreme, a | on an interface could be advertised, while at the other extreme, a | |||
single aggregated value of the available bandwidth per link could be | single aggregated value of the available bandwidth per link could be | |||
advertised. | advertised. | |||
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Consider first the relatively simple structure of SONET and its most | Consider first the relatively simple structure of SONET and its most | |||
common current and planned usage. DS1s and DS3s are the signals most | common current and planned usage. DS1s and DS3s are the signals most | |||
often carried within a SONET STS-1. Either a single DS3 occupies | often carried within a SONET STS-1. Either a single DS3 occupies | |||
the STS-1 or up to 28 DS1s (4 each within the 7 VT groups) are | the STS-1 or up to 28 DS1s (4 each within the 7 VT groups) are | |||
carried within the STS-1. With a reasonable VT1.5 placement | carried within the STS-1. With a reasonable VT1.5 placement | |||
algorithm within each node it may be possible to just report on | algorithm within each node it may be possible to just report on | |||
aggregate bandwidth usage in terms of number of whole STS-1s | aggregate bandwidth usage in terms of number of whole STS-1s | |||
(dedicated to DS3s) used and the number of STS-1s dedicated to | (dedicated to DS3s) used and the number of STS-1s dedicated to | |||
carrying DS1s allocated for this purpose. This way a network | carrying DS1s allocated for this purpose. This way a network | |||
skipping to change at line 1110 | skipping to change at line 1107 | |||
the paths that would be selected in response to a request to set up | the paths that would be selected in response to a request to set up | |||
a batch of connections between a set of endpoints in order to | a batch of connections between a set of endpoints in order to | |||
optimize network link utilization. One can think of this along the | optimize network link utilization. One can think of this along the | |||
lines of global or local optimization of the network in time. | lines of global or local optimization of the network in time. | |||
Due to the complexity of some of the connection routing algorithms | Due to the complexity of some of the connection routing algorithms | |||
(high dimensionality, non-linear integer programming problems) and | (high dimensionality, non-linear integer programming problems) and | |||
various criteria by which one may optimize a network, it may not be | various criteria by which one may optimize a network, it may not be | |||
possible or desirable to run these algorithms on network nodes. | possible or desirable to run these algorithms on network nodes. | |||
However, it may still be desirable to have some basic path | However, it may still be desirable to have some basic path | |||
computation ability running on the network nodes, particularly for | ||||
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computation ability running on the network nodes, particularly for | ||||
use during restoration situations. Such an approach is in line with | use during restoration situations. Such an approach is in line with | |||
the use of MPLS for traffic engineering, but is much different than | the use of MPLS for traffic engineering, but is much different than | |||
typical OSPF or IS-IS usage where all nodes must run the same | typical OSPF or IS-IS usage where all nodes must run the same | |||
routing algorithm. | routing algorithm. | |||
7. LSP Provisioning/Signaling for SDH/SONET | 7. LSP Provisioning/Signaling for SDH/SONET | |||
Traditionally, end-to-end circuit connections in SDH/SONET networks | Traditionally, end-to-end circuit connections in SDH/SONET networks | |||
have been set up via network management systems (NMSs), which issue | have been set up via network management systems (NMSs), which issue | |||
commands (usually under the control of a human operator) to the | commands (usually under the control of a human operator) to the | |||
various network elements involved in the circuit, via an equipment | various network elements involved in the circuit, via an equipment | |||
vendor's element management system (EMS). Very little multi-vendor | vendor's element management system (EMS). Very little multi-vendor | |||
interoperability has been achieved via management systems. Hence, | interoperability has been achieved via management systems. Hence, end- | |||
end-to-end circuits in a multi-vendor environment typically require | to-end circuits in a multi-vendor environment typically require the | |||
the use of multiple management systems and the infamous | use of multiple management systems and the infamous configuration via | |||
configuration via "yellow sticky notes". As discussed in Section 2, | "yellow sticky notes". As discussed in Section 2, a common signaling | |||
a common signaling protocol, such as RSVP with TE extensions or CR- | protocol, such as RSVP with TE extensions or CR- LDP appropriately | |||
LDP appropriately extended for circuit switching applications, could | extended for circuit switching applications, could therefore help to | |||
therefore help to solve these interoperability problems. In this | solve these interoperability problems. In this section, we examine the | |||
section, we examine the various components involved in the automated | various components involved in the automated provisioning of SONET/SDH | |||
provisioning of SONET/SDH LSPs. | LSPs. | |||
7.1.1. What do we Label in SDH/SONET? Frames or Circuits? | 7.1.1. What do we Label in SDH/SONET? Frames or Circuits? | |||
MPLS was initially introduced to control asynchronous technologies | MPLS was initially introduced to control asynchronous technologies | |||
like IP, where a label was attached to each individual block of | like IP, where a label was attached to each individual block of | |||
data, such as an IP packet or a Frame Relay frame. SONET and SDH, | data, such as an IP packet or a Frame Relay frame. SONET and SDH, | |||
however, are synchronous technologies that define a multiplexing | however, are synchronous technologies that define a multiplexing | |||
structure (see Section 3), which we referred to as the SDH (or | structure (see Section 3), which we referred to as the SDH (or | |||
SONET) multiplex. This multiplex involves a hierarchy of signals, | SONET) multiplex. This multiplex involves a hierarchy of signals, | |||
lower order signals embedded within successive higher order ones | lower order signals embedded within successive higher order ones | |||
skipping to change at line 1167 | skipping to change at line 1164 | |||
For instance, the payload of an SDH STM-1 frame does not fully | For instance, the payload of an SDH STM-1 frame does not fully | |||
contain a complete unit of user data. In fact, the user data is | contain a complete unit of user data. In fact, the user data is | |||
contained in a virtual container (VC) that is allowed to float over | contained in a virtual container (VC) that is allowed to float over | |||
two contiguous frames for synchronization purposes. A pointer in the | two contiguous frames for synchronization purposes. A pointer in the | |||
Section Overhead (SOH) indicates the beginning of the VC in the | Section Overhead (SOH) indicates the beginning of the VC in the | |||
payload. Thus, frames are now inter-related, since each consecutive | payload. Thus, frames are now inter-related, since each consecutive | |||
pair may share a common virtual container. From the point of view of | pair may share a common virtual container. From the point of view of | |||
GMPLS, therefore, it is not the successive frames that are treated | GMPLS, therefore, it is not the successive frames that are treated | |||
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independently or labeled, but rather the entire user signal. An | independently or labeled, but rather the entire user signal. An | |||
identical argument applies to SONET. | identical argument applies to SONET. | |||
Observe also that the GMPLS signaling used to control the SDH/SONET | Observe also that the GMPLS signaling used to control the SDH/SONET | |||
multiplex must honor its hierarchy. In other words, the SDH/SONET | multiplex must honor its hierarchy. In other words, the SDH/SONET | |||
layer should not be viewed as homogeneous and flat, because this | layer should not be viewed as homogeneous and flat, because this | |||
would limit the scope of the services that SDH/SONET can provide. | would limit the scope of the services that SDH/SONET can provide. | |||
Instead, GMPLS tunnels should be used to dynamically and | Instead, GMPLS tunnels should be used to dynamically and | |||
hierarchically control the SDH/SONET multiplex. For example, one | hierarchically control the SDH/SONET multiplex. For example, one | |||
skipping to change at line 1224 | skipping to change at line 1221 | |||
difficult to match a label with the corresponding signal, since , as | difficult to match a label with the corresponding signal, since , as | |||
we saw in Section 7.1.1, the label is not coded in the SDH/SONET | we saw in Section 7.1.1, the label is not coded in the SDH/SONET | |||
overhead of the signal. | overhead of the signal. | |||
Another way is to use the well-defined and finite structure of the | Another way is to use the well-defined and finite structure of the | |||
SDH/SONET multiplexing tree to devise a signal numbering scheme that | SDH/SONET multiplexing tree to devise a signal numbering scheme that | |||
makes use of the multiplex as a naming tree, and assigns each | makes use of the multiplex as a naming tree, and assigns each | |||
multiplex entry a unique associated value. This allows the unique | multiplex entry a unique associated value. This allows the unique | |||
identification of each multiplex entry (signal) in terms of its type | identification of each multiplex entry (signal) in terms of its type | |||
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and position in the multiplex tree. By using this multiplex entry | and position in the multiplex tree. By using this multiplex entry | |||
value itself as the label, we automatically add SDH/SONET semantics | value itself as the label, we automatically add SDH/SONET semantics | |||
to the label! Thus, simply by examining the label, one can now | to the label! Thus, simply by examining the label, one can now | |||
directly deduce the signal that it represents, as well as its | directly deduce the signal that it represents, as well as its | |||
position in the SDH/SONET multiplex. We refer to this as | position in the SDH/SONET multiplex. We refer to this as | |||
multiplex-based labeling. This is the idea that was incorporated in | multiplex-based labeling. This is the idea that was incorporated in | |||
the GMPLS signaling specifications for SDH/SONET [17]. | the GMPLS signaling specifications for SDH/SONET [17]. | |||
7.3. Signaling Elements | 7.3. Signaling Elements | |||
skipping to change at line 1279 | skipping to change at line 1276 | |||
We began with a brief overview of MPLS and SDH/SONET networks, | We began with a brief overview of MPLS and SDH/SONET networks, | |||
discussing current circuit establishment in TDM networks, and | discussing current circuit establishment in TDM networks, and | |||
arguing why SDH/SONET technologies will not be "outdated" in the | arguing why SDH/SONET technologies will not be "outdated" in the | |||
foreseeable future. Next, we looked at MPLS applied to SDH/SONET | foreseeable future. Next, we looked at MPLS applied to SDH/SONET | |||
networks, where we considered why such an application makes sense, | networks, where we considered why such an application makes sense, | |||
and reviewed some MPLS terminology as applied to TDM networks. We | and reviewed some MPLS terminology as applied to TDM networks. We | |||
considered the two main areas of application of MPLS methods to TDM | considered the two main areas of application of MPLS methods to TDM | |||
networks, namely routing and signaling. We reviewed in detail the | networks, namely routing and signaling. We reviewed in detail the | |||
switching capabilities of TDM equipment, and the requirement to | switching capabilities of TDM equipment, and the requirement to | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 23 | Bernstein, Mannie, Sharma Expires August 2003 23 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
learn about the protection capabilities of underlying links, and how | learn about the protection capabilities of underlying links, and how | |||
these influence the available capacity advertisement in TDM | these influence the available capacity advertisement in TDM | |||
networks. We focused briefly on path computation methods, pointing | networks. We focused briefly on path computation methods, pointing | |||
out that these were not subject to standardization. We then examined | out that these were not subject to standardization. We then examined | |||
optical path provisioning or signaling, considering the issue of | optical path provisioning or signaling, considering the issue of | |||
what constitutes an appropriate label for TDM circuits and how this | what constitutes an appropriate label for TDM circuits and how this | |||
label should be structured, and we focused on the importance of | label should be structured, and we focused on the importance of | |||
hierarchical label allocation in a TDM network. Finally, we reviewed | hierarchical label allocation in a TDM network. Finally, we reviewed | |||
the signaling elements involved when setting up an optical TDM | the signaling elements involved when setting up an optical TDM | |||
skipping to change at line 1311 | skipping to change at line 1308 | |||
We acknowledge all the participants of the MPLS and CCAMP WGs, whose | We acknowledge all the participants of the MPLS and CCAMP WGs, whose | |||
constant enquiry about GMPLS issues in TDM networks motivated the | constant enquiry about GMPLS issues in TDM networks motivated the | |||
writing of this document, and whose questions helped shape its | writing of this document, and whose questions helped shape its | |||
contents. Also, thanks to Kireeti Kompella for his careful reading | contents. Also, thanks to Kireeti Kompella for his careful reading | |||
of the last version of this draft, and for his helpful comments and | of the last version of this draft, and for his helpful comments and | |||
feedback. | feedback. | |||
11.Author's Addresses | 11.Author's Addresses | |||
Greg Bernstein | Greg Bernstein | |||
Ciena Corporation | Grotto Networking | |||
10480 Ridgeview Court | ||||
Cupertino, CA 94014 | ||||
Phone: +1 510 573-2237 | Phone: +1 510 573-2237 | |||
E-mail: greg@ciena.com | E-mail: greg@ciena.com | |||
Eric Mannie | Eric Mannie | |||
KPNQwest | InterAir Link | |||
Terhulpsesteenweg 6A | ||||
1560 Hoeilaart - Belgium | Phone: +32 2 790 34 25 | |||
Phone: +32 2 658 56 52 | E-mail: eric_mannie@hotmail.com | |||
Mobile: +32 496 58 56 52 | ||||
Fax: +32 2 658 51 18 | ||||
E-mail: eric.mannie@kpnqwest.com | ||||
Vishal Sharma | Vishal Sharma | |||
Metanoia, Inc. | Metanoia, Inc. | |||
305 Elan Village Lane, Unit 121 | 1600 Villa Street, Unit 352 | |||
San Jose, CA 95134 | Mountain View, CA 94041 | |||
Phone: +1 408 955 0910 | ||||
Phone: +1 650 386 6723 | ||||
Email: v.sharma@ieee.org | Email: v.sharma@ieee.org | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 24 | Bernstein, Mannie, Sharma Expires August 2003 24 | |||
GMPLS based Control of SDH/SONET May 2002 | GMPLS based Control of SDH/SONET February 2003 | |||
Full Copyright Statement | Full Copyright Statement | |||
"Copyright (C) The Internet Society (date). All Rights Reserved. | "Copyright (C) The Internet Society (date). All Rights Reserved. | |||
This document and translations of it may be copied and furnished to | This document and translations of it may be copied and furnished to | |||
others, and derivative works that comment on or otherwise explain it | others, and derivative works that comment on or otherwise explain it | |||
or assist in its implmentation may be prepared, copied, published | or assist in its implmentation may be prepared, copied, published | |||
and distributed, in whole or in part, without restriction of any | and distributed, in whole or in part, without restriction of any | |||
kind, provided that the above copyright notice and this paragraph | kind, provided that the above copyright notice and this paragraph | |||
are included on all such copies and derivative works. However, this | are included on all such copies and derivative works. However, this | |||
skipping to change at line 1370 | skipping to change at line 1364 | |||
[3] Rosen, E., Viswanathan, A., and Callon, R., "Multiprotocol Label | [3] Rosen, E., Viswanathan, A., and Callon, R., "Multiprotocol Label | |||
Switching Architecture", RFC 3031, January 2001. | Switching Architecture", RFC 3031, January 2001. | |||
[4] G.707, Network Node Interface for the Synchronous Digital | [4] G.707, Network Node Interface for the Synchronous Digital | |||
Hierarchy (SDH), International Telecommunication Union, 03/96. | Hierarchy (SDH), International Telecommunication Union, 03/96. | |||
[5] Synchronous Optical Network (SONET) Basic Description including | [5] Synchronous Optical Network (SONET) Basic Description including | |||
Multiplex Structure, Rates, and Formats, ANSI T1.105-1995. | Multiplex Structure, Rates, and Formats, ANSI T1.105-1995. | |||
[6] Berger, L. (Editor), "Generalized MPLS - - Signaling Functional | [6] Berger, L. (Editor), "Generalized MPLS - - Signaling Functional | |||
Description," Internet Draft, Work in Progress, draft-ietf-mpls- | Description," RFC 3472, January 2003. | |||
generalized-signaling-08.txt, April 2002. | ||||
[7] Berger, L. (Editor), "Generalized MPLS Signaling - - RSVP-TE | [7] Berger, L. (Editor), "Generalized MPLS Signaling - - RSVP-TE | |||
Extensions," Internet Draft, Work in Progress, draft-ietf-mpls- | Extensions," RFC 3473, January 2003. | |||
generalized-rsvp-te-07.txt, April 2002. | ||||
[8] Berger, L. (Editor), "Generalized MPLS Signaling - - CR-LDP | [8] Berger, L. (Editor), "Generalized MPLS Signaling - - CR-LDP | |||
Extensions," Internet Draft, Work in Progress, draft-ietf-mpls- | Extensions," RFC 3473, January 2003. | |||
generalized-cr-ldp-06.txt, April 2002. | ||||
[9] Bernstein, G., Yates, J., Saha, D., "IP-Centric Control and | [9] Bernstein, G., Yates, J., Saha, D., "IP-Centric Control and | |||
Management of Optical Transport Networks," IEEE Communications | Management of Optical Transport Networks," IEEE Communications | |||
Mag., Vol. 40, Issue 10, October 2000. | Mag., Vol. 40, Issue 10, October 2000. | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 25 | ||||
GMPLS based Control of SDH/SONET May 2002 | ||||
[10] ANSI T1.105.01-1995, Synchronous Optical Network (SONET) | [10] ANSI T1.105.01-1995, Synchronous Optical Network (SONET) | |||
Automatic Protection Switching, American National Standards | Automatic Protection Switching, American National Standards | |||
Institute. | Institute. | |||
Bernstein, Mannie, Sharma Expires August 2003 25 | ||||
GMPLS based Control of SDH/SONET February 2003 | ||||
[11] G.841, Types and Characteristics of SDH Network Protection | [11] G.841, Types and Characteristics of SDH Network Protection | |||
Architectures, ITU-T, 07/95. | Architectures, ITU-T, 07/95. | |||
[12] Kompella, K., et al, "Routing Extensions in Support of | [12] Kompella, K., et al, "Routing Extensions in Support of | |||
Generalize MPLS, " Internet Draft, Work-in-Progress, draft-ietf- | Generalize MPLS, " Internet Draft, Work-in-Progress, draft-ietf- | |||
ccamp-gmpls-routing-04.txt, April 2002. | ccamp-gmpls-routing-05.txt, August 2002. | |||
[13] Kompella, K., et al, "OSPF Extensions in Support of Generalize | [13] Kompella, K., et al, "OSPF Extensions in Support of Generalize | |||
MPLS," Internet Draft, Work-in-Progress, draft-ietf-ccamp-ospf- | MPLS," Internet Draft, Work-in-Progress, draft-ietf-ccamp-ospf- | |||
extensions-07.txt, May 2002. | extensions-09.txt, December 2002. | |||
[14] Kompella, K., et al, "IS-IS Extensions in Support of Generalize | [14] Kompella, K., et al, "IS-IS Extensions in Support of Generalize | |||
MPLS," Internet Draft, Work-in-Progress, draft-ietf-isis-gmpls- | MPLS," Internet Draft, Work-in-Progress, draft-ietf-isis-gmpls- | |||
extensions-12.txt, May 2002. | extensions-16.txt, August 2002. | |||
[15] Bernstein, G., Sharma, V., Ong, L., ææInter-domain Optical | [15] Bernstein, G., Sharma, V., Ong, L., ææInter-domain Optical | |||
Routing,ÆÆ OSA J. of Optical Networking, vol. 1, no. 2, pp. 80-92. | Routing,ÆÆ OSA J. of Optical Networking, vol. 1, no. 2, pp. 80-92. | |||
[16] Kompella, K., Rekhter, Y., and Berger, L., "Link Bundling in | [16] Kompella, K., Rekhter, Y., and Berger, L., "Link Bundling in | |||
MPLS Traffic Engineering", Internet Draft, Work-in-Progress, | MPLS Traffic Engineering", Internet Draft, Work-in-Progress, | |||
draft-kompella-mpls-bundle-05.txt, Feb. 2001. | draft-ietf-mpls-bundle-04.txt, July 2002. | |||
[17] Mannie, E. (Editor), "GMPLS Extensions for SONET and SDH | [17] Mannie, E. (Editor), "GMPLS Extensions for SONET and SDH | |||
Control", Internet Draft, Work-in-Progress, draft-ietf-ccamp- | Control", Internet Draft, Work-in-Progress, draft-ietf-ccamp- | |||
gmpls-sonet-sdh-04.txt, April 2002. | gmpls-sonet-sdh-07.txt, October 2002. | |||
Bernstein, Mannie, Sharma Informational- Expires August 2002 26 | Bernstein, Mannie, Sharma Expires August 2003 26 | |||
End of changes. | ||||
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