draft-ietf-ccamp-gmpls-routing-00.txt   draft-ietf-ccamp-gmpls-routing-01.txt 
Network Working Group K. Kompella (Juniper Networks) Network Working Group K. Kompella (Juniper Networks)
Internet Draft Y. Rekhter (Juniper Networks) Internet Draft Y. Rekhter (Juniper Networks)
Expiration Date: March 2002 A. Banerjee (Calient Networks) Expiration Date: May 2002 A. Banerjee (Calient Networks)
J. Drake (Calient Networks) J. Drake (Calient Networks)
G. Bernstein (Ciena) G. Bernstein (Ciena)
D. Fedyk (Nortel Networks) D. Fedyk (Nortel Networks)
E. Mannie (GTS Network) E. Mannie (GTS Network)
D. Saha (Tellium) D. Saha (Tellium)
V. Sharma (Metanoia, Inc.) V. Sharma (Metanoia, Inc.)
D. Basak (AcceLight Networks) D. Basak (AcceLight Networks)
Routing Extensions in Support of Generalized MPLS Routing Extensions in Support of Generalized MPLS
draft-ietf-ccamp-gmpls-routing-00.txt draft-ietf-ccamp-gmpls-routing-01.txt
1. Status of this Memo 1. 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. all provisions of Section 10 of RFC2026.
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. Drafts.
skipping to change at page 3, line 26 skipping to change at page 3, line 26
brought up on such links. Second, a Label Switched Path can be brought up on such links. Second, a Label Switched Path can be
advertised as a point-to-point TE link (see [LSP-HIER]); thus, an advertised as a point-to-point TE link (see [LSP-HIER]); thus, an
advertised TE link may be between a pair of nodes that don't have a advertised TE link may be between a pair of nodes that don't have a
routing adjacency with each other. Finally, a number of links may be routing adjacency with each other. Finally, a number of links may be
advertised as a single TE link (perhaps for improved scalability), so advertised as a single TE link (perhaps for improved scalability), so
again, there is no longer a one-to-one association of a regular again, there is no longer a one-to-one association of a regular
routing adjacency and a TE link. routing adjacency and a TE link.
Thus we have a more general notion of a TE link. A TE link is a Thus we have a more general notion of a TE link. A TE link is a
"logical" link that has TE properties. The link is logical in a sense "logical" link that has TE properties. The link is logical in a sense
that it represents a way to map the information about certain that it represents a way to group/map the information about certain
physical resources (and their properties) into the information that physical resources (and their properties) into the information that
is used by Constrained SPF for the purpose of path computation. Some is used by Constrained SPF for the purpose of path computation, and
of the properties of a TE link may be configured on the advertising by GMPLS signaling. This grouping/mapping must be done consistently
Label Switching Router (LSR), others which may be obtained from other at both ends of the link. LMP [LMP] could be used to check/verify
LSRs by means of some protocol, and yet others which may be deduced this consistency.
from the component(s) of the TE link.
Depending on the nature of resources that form a particular TE link,
for the purpose of GMPLS signaling in some cases the combination of
<TE link identifier, label> is sufficient to unambiguously identify
the appropriate resource used by an LSP. In other cases, the
combination of <TE link identifier, label> is not sufficient - such
cases are handled by using the link bundling construct [LINK-BUNDLE]
that allows to identify the resource by <TE link identifier,
Component link identifer, label>.
Some of the properties of a TE link may be configured on the
advertising Label Switching Router (LSR), others which may be
obtained from other LSRs by means of some protocol, and yet others
which may be deduced from the component(s) of the TE link.
A TE link between a pair of LSRs doesn't imply the existence of a A TE link between a pair of LSRs doesn't imply the existence of a
routing adjacency between these LSRs. routing adjacency (e.g., an IGP adjacency) between these LSRs. As we
mentioned above, in certain cases a TE link between a pair of LSRs
could be advertised even if there is no routing adjacency at all
between the LSRs (e.g., when the TE link is a Forwarding Adjacency
(see [LSP-HIER])).
A TE link must have some means by which the advertising LSR can know A TE link must have some means by which the advertising LSR can know
of its liveness (this means may be routing hellos, but is not limited of its liveness (this means may be routing hellos, but is not limited
to routing hellos). When an LSR knows that a TE link is up, and can to routing hellos). When an LSR knows that a TE link is up, and can
determine the TE link's TE properties, the LSR may then advertise determine the TE link's TE properties, the LSR may then advertise
that link to its (regular) neighbors. that link to its (regular) neighbors.
In this document, we call the interfaces over which regular routing In this document, we call the interfaces over which regular routing
adjacencies are established "control channels". adjacencies are established "control channels".
[ISIS-TE] and [OSFP-TE] define the canonical TE properties, and say [ISIS-TE] and [OSFP-TE] define the canonical TE properties, and say
how to associate TE properties to regular (packet-switched) links. how to associate TE properties to regular (packet-switched) links.
This document extends the set of TE properties, and also says how to This document extends the set of TE properties, and also says how to
associate TE properties with non-packet-switched links such as links associate TE properties with non-packet-switched links such as links
between Optical Cross-Connects (OXCs). [LSP-HIER] says how to between Optical Cross-Connects (OXCs). [LSP-HIER] says how to
associate TE properties with links formed by Label Switched Paths; associate TE properties with links formed by Label Switched Paths.
[LINK-BUNDLE] says how to associate TE properties with a "bundle" of
links.
5.1. Excluding data traffic from control channels 5.1. Excluding data traffic from control channels
The control channels between nodes in a GMPLS network, such as OXCs, The control channels between nodes in a GMPLS network, such as OXCs,
SONET cross-connects and/or routers, are generally meant for control SONET cross-connects and/or routers, are generally meant for control
and administrative traffic. These control channels are advertised and administrative traffic. These control channels are advertised
into routing as normal links as mentioned in the previous section; into routing as normal links as mentioned in the previous section;
this allows the routing of (for example) RSVP messages and telnet this allows the routing of (for example) RSVP messages and telnet
sessions. However, if routers on the edge of the optical domain sessions. However, if routers on the edge of the optical domain
attempt to forward data traffic over these channels, the channel attempt to forward data traffic over these channels, the channel
skipping to change at page 5, line 12 skipping to change at page 5, line 23
Other techniques for excluding data traffic from control channels may Other techniques for excluding data traffic from control channels may
also be needed. also be needed.
6. GMPLS Routing Enhancements 6. GMPLS Routing Enhancements
In this section we define the enhancements to the TE properties of In this section we define the enhancements to the TE properties of
GMPLS TE links. Encoding of this information in IS-IS is specified in GMPLS TE links. Encoding of this information in IS-IS is specified in
[GMPLS-ISIS]. Encoding of this information in OSPF is specified in [GMPLS-ISIS]. Encoding of this information in OSPF is specified in
[GMPLS-OSPF]. [GMPLS-OSPF].
6.1. Support for unnumbered interfaces 6.1. Support for unnumbered links
Supporting unnumbered interfaces includes carrying the information
about the identity of the interfaces.
6.1.1. Outgoing Interface Identifier
A link from LSR A to LSR B may be assigned an "outgoing interface
identifier". This identifier is a non-zero 32-bit number that is
assigned by LSR A. This identifier must be unique within the scope of
A.
6.1.2. Incoming Interface Identifier An unnumbered link has to be a point-to-point link. An LSR at each
end of an unnumbered link assigns an identifier to that link. This
identifier is a non-zero 32-bit number that is unique within the
scope of the LSR that assigns it.
Suppose there is a link L from A to B. Suppose further that the link Consider an (unnumbered) link between LSRs A and B. LSR A chooses an
L' from B to A that corresponds to the same interface as L has been idenfitier for that link. So is LSR B. From A's perspective we refer
assigned an outgoing interface identifier by B. The "incoming to the identifier that A assigned to the link as the "link local
interface identifier" for L (from A's point of view) is defined as identifier" (or just "local identifier"), and to the identifier that
the outgoing interface identifier for L' (from B's point of view). B assigned to the link as the "link remote identifier" (or just
"remote identifier"). Likewise, from B's perspective the identifier
that B assigned to the link is the local identifier, and the
identifier that A assigned to the link is the remote identifier.
If no such L' exists (e.g., the interface is unidirectional), A MUST Support for unnumbered links in routing includes carrying information
NOT advertise an Incoming Interface Identifier. If A knows that such about the identifiers of that link. Specifically, when an LSR
an L' exists, but does not know the outgoing interface identifier advertises an unnumbered TE link, the advertisement carries both the
assigned to L' by B, A MAY include the Incoming Interface Identifier local and the remote identifiers of the link. If the LSR doesn't
with a value of 0. know the remote identifier of that link, the LSR should use a value
of 0 as the remote identifier.
6.2. Link Protection Type 6.2. Link Protection Type
The Link Protection Type represents the protection capability that The Link Protection Type represents the protection capability that
exists for a link. It is desirable to carry this information so that exists for a link. It is desirable to carry this information so that
it may be used by the path computation algorithm to set up LSPs with it may be used by the path computation algorithm to set up LSPs with
appropriate protection characteristics. This information is organized appropriate protection characteristics. This information is organized
in a hierarchy where typically the minimum acceptable protection is in a hierarchy where typically the minimum acceptable protection is
specified at path instantiation and a path selection technique is specified at path instantiation and a path selection technique is
used to find a path that satisfies at least the minimum acceptable used to find a path that satisfies at least the minimum acceptable
skipping to change at page 9, line 9 skipping to change at page 9, line 16
If an interface is of type L2SC, it means that the node receiving If an interface is of type L2SC, it means that the node receiving
data over this interface can switch the received frames based on the data over this interface can switch the received frames based on the
layer 2 address. For example, an interface associated with a link layer 2 address. For example, an interface associated with a link
terminating on an ATM switch would be considered L2SC. terminating on an ATM switch would be considered L2SC.
6.4.2. Packet-Switch Capable 6.4.2. Packet-Switch Capable
If an interface is of type PSC-1 through PSC-4, it means that the If an interface is of type PSC-1 through PSC-4, it means that the
node receiving data over this interface can switch the received data node receiving data over this interface can switch the received data
on a packet-by-packet basis. The various levels of PSC establish a on a packet-by-packet basis, based on the label carried in the "shim"
hierarchy of LSPs tunneled within LSPs. header [RFC3032]. The various levels of PSC establish a hierarchy of
LSPs tunneled within LSPs.
For Packet-Switch Capable interfaces the additional information For Packet-Switch Capable interfaces the additional information
includes Maximum LSP Bandwidth. includes Maximum LSP Bandwidth, Minimum LSP Bandwidth, and interface
MTU.
For a simple (unbundled) link its Maximum LSP Bandwidth at priority p For a simple (unbundled) link its Maximum LSP Bandwidth at priority p
is defined to be the smaller of its unreserved bandwidth at priority is defined to be the smaller of its unreserved bandwidth at priority
p and its Maximum Reservable Bandwidth. p and its Maximum Reservable Bandwidth. Maximum LSP Bandwidth for a
bundled link is defined in [LINK-BUNDLE].
The Maximum LSP Bandwidth of a bundled link at priority p is defined
to be the maximum of the Maximum LSP Bandwidth at priority p of each
component link.
The Maximum LSP Bandwidth takes the place of the Maximum Bandwidth The Maximum LSP Bandwidth takes the place of the Maximum Bandwidth
([ISIS-TE], [OSPF-TE]). However, while Maximum Bandwidth is a single ([ISIS-TE], [OSPF-TE]). However, while Maximum Bandwidth is a single
fixed value (usually simply the link capacity), Maximum LSP Bandwidth fixed value (usually simply the link capacity), Maximum LSP Bandwidth
is carried per priority, and may vary as LSPs are set up and torn is carried per priority, and may vary as LSPs are set up and torn
down. down.
Although Maximum Bandwidth is to be deprecated, for backward Although Maximum Bandwidth is to be deprecated, for backward
compatibility, one MAY set the Maximum Bandwidth to the Maximum LSP compatibility, one MAY set the Maximum Bandwidth to the Maximum LSP
Bandwidth at priority 7. Bandwidth at priority 7.
The Minimum LSP Bandwidth specifies the minimum bandwidth an LSP
could reserve.
Typical values for the Minimum LSP Bandwidth and for the Maximum LSP
Bandwidth are enumerated in [GMPLS-SIG].
On a PSC interface that supports Standard SONET (or Standard SDH)
encoding, an LSP at priority p could reserve any bandwidth allowed by
the branch of the SONET/SDH hierarchy, with the leaf and the root of
the branch being defined by the Minimum LSP Bandwidth and the Maximum
LSP Bandwidth at priority p.
On a PSC interface that supports Arbitrary SONET (or Arbitrary SDH)
encoding, an LSP at priority p could reserve any bandwidth between
the Minimum LSP Bandwidth and the Maximum LSP Bandwidth at priority
p, provided that the bandwidth reserved by the LSP is a multiple of
the Minimum LSP Bandwidth.
The Interface MTU is the maximum size of a packet that can be
transmitted on this interface without being fragmented.
6.4.3. Time-Division Multiplex Capable 6.4.3. Time-Division Multiplex Capable
If an interface is of type TDM, it means that the node receiving data If an interface is of type TDM, it means that the node receiving data
over this interface can multiplex or demultiplex channels within a over this interface can multiplex or demultiplex channels within a
SONET/SDH payload. SONET/SDH payload.
For Time-Division Multiplex Capable interfaces the additional For Time-Division Multiplex Capable interfaces the additional
information includes Maximum LSP Bandwidth, the information on information includes Maximum LSP Bandwidth, the information on
whether the interface supports Standard or Arbitrary SONET/SDH, and whether the interface supports Standard or Arbitrary SONET/SDH, and
Minimum LSP Bandwidth. Minimum LSP Bandwidth.
For a simple (unbundled) link the Maximum LSP Bandwidth at priority p For a simple (unbundled) link the Maximum LSP Bandwidth at priority p
is defined as the maximum bandwidth an LSP at priority p could is defined as the maximum bandwidth an LSP at priority p could
reserve. reserve. Maximum LSP Bandwidth for a bundled link is defined in
[LINK-BUNDLE].
The Maximum LSP Bandwidth of a bundled link at priority p is defined
to be the maximum of the Maximum LSP Bandwidth at priority p of each
component link.
The Minimum LSP Bandwidth specifies the minimum bandwidth an LSP The Minimum LSP Bandwidth specifies the minimum bandwidth an LSP
could reserve. could reserve.
Typical values for the Minimum LSP Bandwidth and for the Maximum LSP Typical values for the Minimum LSP Bandwidth and for the Maximum LSP
Bandwidth are enumerated in [GMPLS-SIG]. Bandwidth are enumerated in [GMPLS-SIG].
On an interface having Standard SONET (or Standard SDH) multiplexing, On an interface having Standard SONET (or Standard SDH) multiplexing,
an LSP at priority p could reserve any bandwidth allowed by the an LSP at priority p could reserve any bandwidth allowed by the
branch of the SONET/SDH hierarchy, with the leaf and the root of the branch of the SONET/SDH hierarchy, with the leaf and the root of the
skipping to change at page 11, line 27 skipping to change at page 12, line 5
An interface that connects a link to an LSR may support not one, but An interface that connects a link to an LSR may support not one, but
several Interface Switching Capabilities. For example, consider a several Interface Switching Capabilities. For example, consider a
fiber link carrying a set of lambdas that terminates on an LSR fiber link carrying a set of lambdas that terminates on an LSR
interface that could either cross-connect one of these lambdas to interface that could either cross-connect one of these lambdas to
some other outgoing optical channel, or could terminate the lamdba, some other outgoing optical channel, or could terminate the lamdba,
and extract (demultiplex) data from that lambda using TDM, and then and extract (demultiplex) data from that lambda using TDM, and then
cross-connect these TDM channels to some outgoing TDM channels. To cross-connect these TDM channels to some outgoing TDM channels. To
support this a Link State Advertisement may carry a list of Interface support this a Link State Advertisement may carry a list of Interface
Switching Capabilities Descriptors. Switching Capabilities Descriptors.
6.4.7. Other issues 6.4.7. Interface Switching Capabilities and Labels
Depicting a TE link as a tuple that contains Interface Switching
Capabilities at both ends of the link, some examples links may be:
[PSC, PSC] - a link between two packet LSRs
[TDM, TDM] - a link between two Digital Cross Connects
[LSC, LSC] - a link between two OXCs
[PSC, TDM] - a link between a packet LSR and a Digital Cross Connect
[PSC, LSC] - a link between a packet LSR and an OXC
[TDM, LSC] - a link between a Digital Cross Connect and an OXC
Both ends of a given TE link has to use the same way of carrying
label information over that link. Carrying label information on a
given TE link depends on the Interface Switching Capability at both
ends of the link, and is determined as follows:
[PSC, PSC] - label is carried in the "shim" header [RFC3032]
[TDM, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
[LSC, LSC] - label represents a port on an OXC
[PSC, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
[PSC, LSC] - label represents a port
[TDM, LSC] - label represents a port
6.4.8. Other issues
It is possible that Interface Switching Capability Descriptor will It is possible that Interface Switching Capability Descriptor will
change over time, reflecting the allocation/deallocation of LSPs. change over time, reflecting the allocation/deallocation of LSPs.
For example, assume that STS-1, STS-3c, STS-12c, STS-48c and STS-192c For example, assume that STS-1, STS-3c, STS-12c, STS-48c and STS-192c
LSPs can be established on a OC-192 interface whose Encoding Type is LSPs can be established on a OC-192 interface whose Encoding Type is
SONET (or to be more precise, SONET ANSI T1.105-1995). Thus, SONET (or to be more precise, SONET ANSI T1.105-1995). Thus,
initially in the Interface Switching Capability Descriptor the initially in the Interface Switching Capability Descriptor the
Minimum LSP Bandwidth is set to STS-1, and Maximum LSP Bandwidth is Minimum LSP Bandwidth is set to STS-1, and Maximum LSP Bandwidth is
set to STS-192 for all priorities. As soon as an LSP of STS-1 size set to STS-192 for all priorities. As soon as an LSP of STS-1 size
at priority 1 is established on the interface, it is no longer at priority 1 is established on the interface, it is no longer
skipping to change at page 12, line 5 skipping to change at page 13, line 5
indicating that the Maximum LSP Bandwidth is no longer STS-192, but indicating that the Maximum LSP Bandwidth is no longer STS-192, but
STS-48 for all but priority 0 (at priority 0 the Maximum LSP STS-48 for all but priority 0 (at priority 0 the Maximum LSP
Bandwidth is still STS-192). If subsequently there is another STS-1 Bandwidth is still STS-192). If subsequently there is another STS-1
LSP, there is no change in the Interface Switching Capability LSP, there is no change in the Interface Switching Capability
Descriptor. The Descriptor remains the same until the node can no Descriptor. The Descriptor remains the same until the node can no
longer establish a STS-48c LSP over the interface (which means that longer establish a STS-48c LSP over the interface (which means that
at this point more than 144 time slots are taken by LSPs on the at this point more than 144 time slots are taken by LSPs on the
interface). Once this happened, the Descriptor is modified again, interface). Once this happened, the Descriptor is modified again,
and the modified Descriptor is advertised to other nodes. and the modified Descriptor is advertised to other nodes.
6.4.8. Examples of Interface Switching Capability Descriptor 6.4.9. Examples of Interface Switching Capability Descriptor
6.4.8.1. STS-48 POS Interface on a LSR 6.4.9.1. STS-48 POS Interface on a LSR
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = PSC-1 Interface Switching Capability = PSC-1
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Max LSP Bandwidth[p] = 2.5 Gbps, for all p Max LSP Bandwidth[p] = 2.5 Gbps, for all p
If multiple links with such interfaces were to be advertised as one If multiple links with such interfaces at both ends were to be
TE link, link bundling techniques should be used. advertised as one TE link, link bundling techniques should be used.
6.4.8.2. GigE Packet Interface on a LSR 6.4.9.2. GigE Packet Interface on a LSR
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = PSC-1 Interface Switching Capability = PSC-1
Encoding = Ethernet 802.3 Encoding = Ethernet 802.3
Max LSP Bandwidth[p] = 1.0 Gbps, for all p Max LSP Bandwidth[p] = 1.0 Gbps, for all p
If multiple links with such interfaces were to be advertised as one If multiple links with such interfaces at both ends were to be
TE link, link bundling techniques should be used. advertised as one TE link, link bundling techniques should be used.
6.4.8.3. OC-192 SONET Interface on a Digital Cross Connect with Standard 6.4.9.3. OC-192 SONET Interface on a Digital Cross Connect with Standard
SONET SONET
Consider a branch of SONET multiplexing tree : VT-1.5, STS-1, STS-3c, Consider a branch of SONET multiplexing tree : VT-1.5, STS-1, STS-3c,
STS-12c, STS-48c, STS-192c. If it is possible to establish all these STS-12c, STS-48c, STS-192c. If it is possible to establish all these
connections on a OC-192 interface, the Interface Switching Capability connections on a OC-192 interface, the Interface Switching Capability
Descriptor of that interface can be advertised as follows: Descriptor of that interface can be advertised as follows:
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = TDM [Standard SONET] Interface Switching Capability = TDM [Standard SONET]
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Min LSP Bandwidth = VT1.5 Min LSP Bandwidth = VT1.5
Max LSP Bandwidth[p] = STS192, for all p Max LSP Bandwidth[p] = STS192, for all p
If multiple links with such interfaces were to be advertised as one If multiple links with such interfaces at both ends were to be
TE link, link bundling techniques should be used. advertised as one TE link, link bundling techniques should be used.
6.4.8.4. OC-192 SONET Interface on a Digital Cross Connect with two 6.4.9.4. OC-192 SONET Interface on a Digital Cross Connect with two
types of SONET multiplexing hierarchy supported types of SONET multiplexing hierarchy supported
Interface Switching Capability Descriptor 1: Interface Switching Capability Descriptor 1:
Interface Switching Capability = TDM [Standard SONET] Interface Switching Capability = TDM [Standard SONET]
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Min LSP Bandwidth = VT1.5 Min LSP Bandwidth = VT1.5
Max LSP Bandwidth[p] = STS192, for all p Max LSP Bandwidth[p] = STS192, for all p
Interface Switching Capability Descriptor 2: Interface Switching Capability Descriptor 2:
Interface Switching Capability = TDM [Arbitrary SONET] Interface Switching Capability = TDM [Arbitrary SONET]
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Min LSP Bandwidth = VT2 Min LSP Bandwidth = VT2
Max LSP Bandwidth[p] = STS192, for all p Max LSP Bandwidth[p] = STS192, for all p
If multiple links with such interfaces were to be advertised as one If multiple links with such interfaces at both ends were to be
TE link, link bundling techniques should be used. advertised as one TE link, link bundling techniques should be used.
6.4.8.5. Interface on an opaque OXC (SONET framed) 6.4.9.5. Interface on an opaque OXC (SONET framed)
An "opaque OXC" is considered operationally an OXC, as the whole An "opaque OXC" is considered operationally an OXC, as the whole
lambda (carrying the SONET line) is switched transparently without lambda (carrying the SONET line) is switched transparently without
further multiplexing/demultiplexing, and either none of the SONET further multiplexing/demultiplexing, and either none of the SONET
overhead bytes, or at least the important ones are not changed. overhead bytes, or at least the important ones are not changed.
An interface on an opaque OXC handles a single wavelength, and An interface on an opaque OXC handles a single wavelength, and
cannot switch multiple wavelengths as a whole. Thus, an interface on cannot switch multiple wavelengths as a whole. Thus, an interface on
an opaque OXC is always LSC, and not FSC, irrespective of whether an opaque OXC is always LSC, and not FSC, irrespective of whether
there is DWDM external to it. there is DWDM external to it.
skipping to change at page 14, line 5 skipping to change at page 15, line 5
SIG]). SIG]).
The following is an example of an interface switching capability The following is an example of an interface switching capability
descriptor on a SONET framed opaque OXC: descriptor on a SONET framed opaque OXC:
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = LSC Interface Switching Capability = LSC
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Reservable Bandwidth = Determined by SONET Framer (say OC192) Reservable Bandwidth = Determined by SONET Framer (say OC192)
6.4.8.6. Interface on a transparent OXC (PXC) with external DWDM that 6.4.9.6. Interface on a transparent OXC (PXC) with external DWDM that
understands SONET framing understands SONET framing
This example assumes that DWDM and PXC are connected in such a way This example assumes that DWDM and PXC are connected in such a way
that each interface (port) on the PXC handles just a single that each interface (port) on the PXC handles just a single
wavelength. Thus, even if in principle an interface on the PXC could wavelength. Thus, even if in principle an interface on the PXC could
switch multiple wavelengths as a whole, in this particular case an switch multiple wavelengths as a whole, in this particular case an
interface on the PXC is considered LSC, and not FSC. interface on the PXC is considered LSC, and not FSC.
_______ _______
| | | |
skipping to change at page 14, line 38 skipping to change at page 15, line 38
The following is an example of an interface switching capability The following is an example of an interface switching capability
descriptor on a transparent OXC (PXC) with external DWDM that descriptor on a transparent OXC (PXC) with external DWDM that
understands SONET framing: understands SONET framing:
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = LSC Interface Switching Capability = LSC
Encoding = SONET ANSI T1.105-1995 (comes from DWDM) Encoding = SONET ANSI T1.105-1995 (comes from DWDM)
Reservable Bandwidth = Determined by DWDM (say OC192) Reservable Bandwidth = Determined by DWDM (say OC192)
6.4.8.7. Interface on a transparent OXC (PXC) with external DWDM that is 6.4.9.7. Interface on a transparent OXC (PXC) with external DWDM that is
transparent to bit-rate and framing transparent to bit-rate and framing
This example assumes that DWDM and PXC are connected in such a way This example assumes that DWDM and PXC are connected in such a way
that each interface (port) on the PXC handles just a single that each interface (port) on the PXC handles just a single
wavelength. Thus, even if in principle an interface on the PXC could wavelength. Thus, even if in principle an interface on the PXC could
switch multiple wavelengths as a whole, in this particular case an switch multiple wavelengths as a whole, in this particular case an
interface on the PXC is considered LSC, and not FSC. interface on the PXC is considered LSC, and not FSC.
_______ _______
| | | |
skipping to change at page 15, line 25 skipping to change at page 16, line 25
The following is an example of an interface switching capability The following is an example of an interface switching capability
descriptor on a transparent OXC (PXC) with external DWDM that is descriptor on a transparent OXC (PXC) with external DWDM that is
transparent to bit-rate and framing: transparent to bit-rate and framing:
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = LSC Interface Switching Capability = LSC
Encoding = Photonic Encoding = Photonic
Reservable Bandwidth = Determined by optical technology limits Reservable Bandwidth = Determined by optical technology limits
6.4.8.8. Interface on a PXC with no external DWDM 6.4.9.8. Interface on a PXC with no external DWDM
The absence of DWDM in between two PXCs, implies that an interface is The absence of DWDM in between two PXCs, implies that an interface is
not limited to one wavelength. Thus, the interface is advertised as not limited to one wavelength. Thus, the interface is advertised as
FSC. FSC.
A TE link is a group of interfaces on the PXC. All interfaces on a A TE link is a group of interfaces on the PXC. All interfaces on a
given PXC are required to have identifiers unique to that PXC, and given PXC are required to have identifiers unique to that PXC, and
these identifiers are used as port labels (see 3.2.1.1 of [GMPLS- these identifiers are used as port labels (see 3.2.1.1 of [GMPLS-
SIG]). SIG]).
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = FSC Interface Switching Capability = FSC
Encoding = Photonic Encoding = Photonic
Reservable Bandwidth = Determined by optical technology limits Reservable Bandwidth = Determined by optical technology limits
Note that this example assumes that the PXC does not restrict each Note that this example assumes that the PXC does not restrict each
port to carry only one wavelength. port to carry only one wavelength.
6.4.9. Example of interfaces that support multiple switching 6.4.10. Example of interfaces that support multiple switching
capabilities capabilities
There can be many combinations possible, some are described below. There can be many combinations possible, some are described below.
6.4.9.1. Interface on a PXC+TDM device with external DWDM 6.4.10.1. Interface on a PXC+TDM device with external DWDM
As discussed earlier, the presence of the external DWDM limits that As discussed earlier, the presence of the external DWDM limits that
only one wavelength be on a port of the PXC. On such a port, the only one wavelength be on a port of the PXC. On such a port, the
attached PXC+TDM device can do one of the following. The wavelength attached PXC+TDM device can do one of the following. The wavelength
may be cross-connected by the PXC element to other out-bound optical may be cross-connected by the PXC element to other out-bound optical
channel, or the wavelength may be terminated as a SONET interface and channel, or the wavelength may be terminated as a SONET interface and
SONET channels switched. SONET channels switched.
From a GMPLS perspective the PXC+TDM functionality is treated as a From a GMPLS perspective the PXC+TDM functionality is treated as a
single interface. The interface is described using two Interface single interface. The interface is described using two Interface
skipping to change at page 16, line 32 skipping to change at page 17, line 32
Reservable Bandwidth = OC192 Reservable Bandwidth = OC192
and and
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = TDM [Standard SONET] Interface Switching Capability = TDM [Standard SONET]
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Min LSP Bandwidth = VT1.5 Min LSP Bandwidth = VT1.5
Max LSP Bandwidth[p] = STS192, for all p Max LSP Bandwidth[p] = STS192, for all p
6.4.9.2. Interface on an opaque OXC+TDM device with external DWDM 6.4.10.2. Interface on an opaque OXC+TDM device with external DWDM
An interface on an "opaque OXC+TDM" device would also be advertised An interface on an "opaque OXC+TDM" device would also be advertised
as LSC+TDM much the same way as the previous case. as LSC+TDM much the same way as the previous case.
6.4.9.3. Interface on a PXC+LSR device with external DWDM 6.4.10.3. Interface on a PXC+LSR device with external DWDM
As discussed earlier, the presence of the external DWDM limits that As discussed earlier, the presence of the external DWDM limits that
only one wavelength be on a port of the PXC. On such a port, the only one wavelength be on a port of the PXC. On such a port, the
attached PXC+LSR device can do one of the following. The wavelength attached PXC+LSR device can do one of the following. The wavelength
may be cross-connected by the PXC element to other out-bound optical may be cross-connected by the PXC element to other out-bound optical
channel, or the wavelength may be terminated as a Packet interface channel, or the wavelength may be terminated as a Packet interface
and packets switched. and packets switched.
From a GMPLS perspective the PXC+LSR functionality is treated as a From a GMPLS perspective the PXC+LSR functionality is treated as a
single interface. The interface is described using two Interface single interface. The interface is described using two Interface
skipping to change at page 17, line 16 skipping to change at page 18, line 16
Encoding = SONET ANSI T1.105-1995 (comes from WDM) Encoding = SONET ANSI T1.105-1995 (comes from WDM)
Reservable Bandwidth = OC192 Reservable Bandwidth = OC192
and and
Interface Switching Capability Descriptor: Interface Switching Capability Descriptor:
Interface Switching Capability = PSC-1 Interface Switching Capability = PSC-1
Encoding = SONET ANSI T1.105-1995 Encoding = SONET ANSI T1.105-1995
Max LSP Bandwidth[p] = 10 Gbps, for all p Max LSP Bandwidth[p] = 10 Gbps, for all p
6.4.9.4. Interface on a TDM+LSR device 6.4.10.4. Interface on a TDM+LSR device
On a TDM+LSR device that offers a channelized SONET/SDH interface the On a TDM+LSR device that offers a channelized SONET/SDH interface the
following may be possible: following may be possible:
- A subset of the SONET/SDH channels may be uncommitted. That is, - A subset of the SONET/SDH channels may be uncommitted. That is,
they are not currently in use and hence are available for they are not currently in use and hence are available for
allocation. allocation.
- A second subset of channels may already be committed for transit - A second subset of channels may already be committed for transit
purposes. That is, they are already cross-connected by the purposes. That is, they are already cross-connected by the
skipping to change at page 18, line 41 skipping to change at page 19, line 41
Extensions in Support of Generalized MPLS", draft-ietf-isis-gmpls- Extensions in Support of Generalized MPLS", draft-ietf-isis-gmpls-
extensions-02.txt (work in progress) extensions-02.txt (work in progress)
[GMPLS-OSPF] Kompella, K., Rekhter, Y., Banerjee, A. et al, "OSPF [GMPLS-OSPF] Kompella, K., Rekhter, Y., Banerjee, A. et al, "OSPF
Extensions in Support of Generalized MPLS", draft-ietf-ccamp-ospf- Extensions in Support of Generalized MPLS", draft-ietf-ccamp-ospf-
gmpls-extensions-00.txt (work in progress) gmpls-extensions-00.txt (work in progress)
[LINK-BUNDLE] Kompella, K., Rekhter, Y., Berger, L., "Link Bundling [LINK-BUNDLE] Kompella, K., Rekhter, Y., Berger, L., "Link Bundling
in MPLS Traffic Engineering", draft-ietf-mpls-bundle-00.txt (work in in MPLS Traffic Engineering", draft-ietf-mpls-bundle-00.txt (work in
progress) progress)
[LMP]
[OVPN] Ould-Brahim, H., Rekhter, Y., Fedyk, D., Ashwood-Smith, P., [OVPN] Ould-Brahim, H., Rekhter, Y., Fedyk, D., Ashwood-Smith, P.,
Rosen, E., Mannie, E., Fang, L., Drake, J., "BGP/GMPLS Optical VPNs", Rosen, E., Mannie, E., Fang, L., Drake, J., "BGP/GMPLS Optical VPNs",
draft-ouldbrahim-bgpgmpls-ovpn-01.txt (work in progress) draft-ouldbrahim-bgpgmpls-ovpn-01.txt (work in progress)
10. Authors' Information 10. Authors' Information
Kireeti Kompella Kireeti Kompella
Juniper Networks, Inc. Juniper Networks, Inc.
1194 N. Mathilda Ave 1194 N. Mathilda Ave
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/