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Versions: (draft-rabbat-ccamp-rfc3946bis) 00
01 RFC 4606
Network Working Group E. Mannie
Internet Draft Consultant
Replaces RFC 3946 D. Papadimitriou
Category: Standard Track Alcatel
Expiration Date: May 2006
December 2005
Generalized Multi-Protocol Label Switching (GMPLS) Extensions
for Synchronous Optical Network (SONET)
and Synchronous Digital Hierarchy (SDH) Control
draft-ietf-ccamp-rfc3946bis-01.txt
Status of this Memo
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Copyright Notice
Copyright (C) The Internet Society (2005). All Rights Reserved.
Abstract
This document provides minor clarification to RFC 3946.
This document is a companion to the Generalized Multi-Protocol
Label Switching (GMPLS) signaling. It defines the Synchronous
Optical Network (SONET)/Synchronous Digital Hierarchy (SDH)
technology specific information needed when using GMPLS signaling.
E.Mannie & D.Papadimitriou (Editors) 1
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Table of Contents
1. Introduction .............................................. 2
2. SONET and SDH Traffic Parameters .......................... 2
2.1. SONET/SDH Traffic Parameters ........................ 3
2.2. RSVP-TE Details ..................................... 9
2.3. CR-LDP Details ...................................... 9
3. SONET and SDH Labels ...................................... 10
4. Acknowledgments ........................................... 15
5. Security Considerations ................................... 16
6. IANA Considerations ....................................... 16
7. References ................................................ 16
7.1. Normative References ................................ 16
Appendix 1 - Signal Type Values Extension for VC-3 ............ 18
Annex 1 - Examples ............................................ 18
Contributors .................................................. 21
Authors' Addresses ............................................ 25
Full Copyright Statement ...................................... 26
1. Introduction
As described in [RFC3945], Generalized MPLS (GMPLS) extends MPLS
from supporting packet (Packet Switching Capable - PSC) interfaces
and switching to include support of four new classes of interfaces
and switching: Layer-2 Switch Capable (L2SC), Time-Division
Multiplex (TDM), Lambda Switch Capable (LSC) and Fiber-Switch
Capable (FSC). A functional description of the extensions to MPLS
signaling needed to support the new classes of interfaces and
switching is provided in [RFC3471]. [RFC3473] describes RSVP-TE
specific formats and mechanisms needed to support all five classes
of interfaces, and CR-LDP extensions can be found in [RFC3472].
This document presents details that are specific to Synchronous
Optical Network (SONET)/Synchronous Digital Hierarchy (SDH). Per
[RFC3471], SONET/SDH specific parameters are carried in the
signaling protocol in traffic parameter specific objects.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
in this document are to be interpreted as described in [RFC2119].
Moreover, the reader is assumed to be familiar with the
terminology in ANSI [T1.105], ITU-T [G.707] as well as [RFC3471],
[RFC3472], and [RFC3473]. The following abbreviations are used in
this document:
DCC: Data Communications Channel.
LOVC: Lower Order Virtual Container
HOVC: Higher Order Virtual Container
MS: Multiplex Section.
MSOH: Multiplex Section overhead.
POH: Path overhead.
RS: Regenerator Section.
RSOH: Regenerator section overhead.
E.Mannie & D.Papadimitriou (Editors) 2
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SDH: Synchronous digital hierarchy.
SOH: Section overhead.
SONET: Synchronous Optical Network.
SPE: Synchronous Payload Envelope.
STM(-N): Synchronous Transport Module (-N) (SDH).
STS(-N): Synchronous Transport Signal-Level N (SONET).
VC-n: Virtual Container-n (SDH).
VTn: Virtual Tributary-n (SONET).
2. SONET and SDH Traffic Parameters
This section defines the GMPLS traffic parameters for SONET/SDH.
The protocol specific formats, for the SONET/SDH-specific RSVP-TE
objects and CR-LDP TLVs are described in sections 2.2 and 2.3
respectively.
These traffic parameters specify indeed a base set of capabilities
for SONET ANSI [T1.105] and SDH ITU-T [G.707] such as
concatenation and transparency. Other documents may further
enhance this set of capabilities in the future. For instance,
signaling for SDH over PDH ITU-T G.832 or sub-STM-0 ITU-T G.708
interfaces could be defined.
The traffic parameters defined hereafter (see Section 2.1) MUST be
used when the label is encoded as SUKLM as defined in this memo
(see Section 3). They MUST also be used when requesting one of
Section/RS or Line/MS overhead transparent STS-1/STM-0, STS-
3*N/STM-N (N=1, 4, 16, 64, 256) signals.
The traffic parameters and label encoding defined in [RFC3471],
Section 3.2, MUST be used for fully transparent STS-1/STM-0, STS-
3*N/STM-N (N=1, 4, 16, 64, 256) signal requests. A fully
transparent signal is one for which all overhead is left
unmodified by intermediate nodes, i.e., when all defined
Transparency (T) bits would be set if the traffic parameters
defined in section 2.1 were used.
2.1. SONET/SDH Traffic Parameters
The traffic parameters for SONET/SDH are organized as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signal Type | RCC | NCC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NVC | Multiplier (MT) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transparency (T) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Profile (P) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Annex 1 lists examples of SONET and SDH signal coding.
E.Mannie & D.Papadimitriou (Editors) 3
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
o) Signal Type (ST): 8 bits
This field indicates the type of Elementary Signal that comprises
the requested LSP. Several transforms can be applied successively
on the Elementary Signal to build the Final Signal being actually
requested for the LSP.
Each transform application is optional and must be ignored if
zero, except the Multiplier (MT) that cannot be zero and is
ignored if equal to one.
Transforms must be applied strictly in the following order:
- First, contiguous concatenation (by using the RCC and NCC
fields) can be optionally applied on the Elementary Signal,
resulting in a contiguously concatenated signal.
- Second, virtual concatenation (by using the NVC field) can be
optionally applied on the Elementary Signal resulting in a
virtually concatenated signal.
- Third, some transparency (by using the Transparency field) can
be optionally specified when requesting a frame as signal rather
than an SPE or VC based signal.
- Fourth, a multiplication (by using the Multiplier field) can be
optionally applied either directly on the Elementary Signal, or on
the contiguously concatenated signal obtained from the first
phase, or on the virtually concatenated signal obtained from the
second phase, or on these signals combined with some transparency.
Permitted Signal Type values for SONET/SDH are:
Value Type (Elementary Signal)
----- ------------------------
1 VT1.5 SPE / VC-11
2 VT2 SPE / VC-12
3 VT3 SPE
4 VT6 SPE / VC-2
5 STS-1 SPE / VC-3
6 STS-3c SPE / VC-4
7 STS-1 / STM-0 (only when requesting transparency)
8 STS-3 / STM-1 (only when requesting transparency)
9 STS-12 / STM-4 (only when requesting transparency)
10 STS-48 / STM-16 (only when requesting transparency)
11 STS-192 / STM-64 (only when requesting transparency)
12 STS-768 / STM-256 (only when requesting transparency)
A dedicated signal type is assigned to a SONET STS-3c SPE instead of
coding it as a contiguous concatenation of three STS-1 SPEs. This is
done in order to provide easy interworking between SONET and SDH
signaling.
Appendix 1 adds one signal type (optional) to the above values.
E.Mannie & D.Papadimitriou (Editors) 4
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o) Requested Contiguous Concatenation (RCC): 8 bits
This field is used to request the optional SONET/SDH contiguous
concatenation of the Elementary Signal.
This field is a vector of flags. Each flag indicates the support
of a particular type of contiguous concatenation. Several flags
can be set at the same time to indicate a choice.
These flags allow an upstream node to indicate to a downstream
node the different types of contiguous concatenation that it
supports. However, the downstream node decides which one to use
according to its own rules.
A downstream node receiving simultaneously more than one flag
chooses a particular type of contiguous concatenation, if any
supported, and based on criteria that are out of this document
scope. A downstream node that doesn't support any of the
concatenation types indicated by the field must refuse the LSP
request. In particular, it must refuse the LSP request if it
doesn't support contiguous concatenation at all.
When several flags have been set, the upstream node retrieves the
(single) type of contiguous concatenation the downstream node has
selected by looking at the position indicated by the first label
and the number of label(s) as returned by the downstream node (see
also Section 3).
The entire field is set to zero to indicate that no contiguous
concatenation is requested at all (default value). A non-zero
field indicates that some contiguous concatenation is requested.
The following flag is defined:
Flag 1 (bit 1): Standard contiguous concatenation.
Flag 1 indicates that the standard SONET/SDH contiguous
concatenation as defined in [T1.105]/[G.707] is supported. Note
that bit 1 is the low order bit. Other flags are reserved for
extensions, if not used they must be set to zero when sent, and
should be ignored when received.
See note 1 hereafter in the section on the NCC about the SONET
contiguous concatenation of STS-1 SPEs when the number of
components is a multiple of three.
o) Number of Contiguous Components (NCC): 16 bits
This field indicates the number of identical SONET SPEs/SDH VCs
(i.e., Elementary Signal) that are requested to be concatenated,
as specified in the RCC field.
Note 1: when requesting a SONET STS-Nc SPE with N=3*X, the
E.Mannie & D.Papadimitriou (Editors) 5
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Elementary Signal to use must always be an STS-3c_SPE signal type
and the value of NCC must always be equal to X. This allows also
facilitating the interworking between SONET and SDH. In
particular, it means that the contiguous concatenation of three
STS-1 SPEs can not be requested because according to this
specification, this type of signal must be coded using the STS-3c
SPE signal type.
Note 2: when requesting a transparent STS-N/STM-N signal limited
to a single contiguously concatenated STS-Nc_SPE/VC-4-Nc, the
signal type must be STS-N/STM-N, RCC with flag 1 and NCC set to 1.
The NCC value must be consistent with the type of contiguous
concatenation being requested in the RCC field. In particular,
this field is irrelevant if no contiguous concatenation is
requested (RCC = 0), in that case it must be set to zero when
sent, and should be ignored when received. A RCC value different
from 0 implies a number of contiguous components greater than or
equal to 1.
Note 3: Following these rules, when requesting a VC-4 signal, the
RCC and the NCC values SHOULD be set to 0 whereas for an STS-3c
SPE signal, the RCC and the NCC values SHOULD be set 1. However,
if local conditions allow and since the setting of the RCC and NCC
values is locally driven, the requesting upstream node MAY set the
RCC and NCC values to either SDH or SONET settings without
impacting the function. Moreover, the downstream node SHOULD
accept the requested values if local conditions allow. If these
values cannot be supported, the receiver downstream node SHOULD
generate a PathErr/NOTIFICATION message (see Section 2.2/2.3,
respectively).
o) Number of Virtual Components (NVC): 16 bits
This field indicates the number of signals that are requested to
be virtually concatenated. These signals are all of the same type
by definition. They are Elementary Signal SPEs/VCs for which
signal types are defined in this document, i.e., VT1.5_SPE/VC-11,
VT2_SPE/VC-12, VT3_SPE, VT6_SPE/VC-2, STS-1_SPE/VC-3 or STS-
3c_SPE/VC-4.
This field is set to 0 (default value) to indicate that no virtual
concatenation is requested.
o) Multiplier (MT): 16 bits
This field indicates the number of identical signals that are
requested for the LSP, i.e., that form the Final Signal. These
signals can be either identical Elementary Signals, or identical
contiguously concatenated signals, or identical virtually
concatenated signals. Note that all these signals belong thus to
the same LSP.
E.Mannie & D.Papadimitriou (Editors) 6
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The distinction between the components of multiple virtually
concatenated signals is done via the order of the labels that are
specified in the signaling. The first set of labels must describe
the first component (set of individual signals belonging to the
first virtual concatenated signal), the second set must describe
the second component (set of individual signals belonging to the
second virtual concatenated signal) and so on.
This field is set to one (default value) to indicate that exactly
one instance of a signal is being requested. Intermediate and
egress nodes MUST verify that the node itself and the interfaces
on which the LSP will be established can support the requested
multiplier value. If the requested values can not be supported,
the receiver node MUST generate a PathErr/NOTIFICATION message
(see Section 2.2/2.3, respectively).
Zero is an invalid value. If received, the node MUST generate a
PathErr/NOTIFICATION message (see Section 2.2/2.3, respectively).
Note 1: when requesting a transparent STS-N/STM-N signal limited
to a single contiguously concatenated STS-Nc-SPE/VC-4-Nc, the
multiplier field MUST be equal to 1 (only valid value).
o) Transparency (T): 32 bits
This field is a vector of flags that indicates the type of
transparency being requested. Several flags can be combined to
provide different types of transparency. Not all combinations are
necessarily valid. The default value for this field is zero, i.e.,
no transparency requested.
Transparency, as defined from the point of view of this signaling
specification, is only applicable to the fields in the SONET/SDH
frame overheads. In the SONET case, these are the fields in the
Section Overhead (SOH), and the Line Overhead (LOH). In the SDH
case, these are the fields in the Regenerator Section Overhead
(RSOH), the Multiplex Section overhead (MSOH), and the pointer
fields between the two. With SONET, the pointer fields are part of
the LOH.
Note as well that transparency is only applicable when using the
following Signal Types: STS-1/STM-0, STS-3/STM-1, STS-12/STM-4,
STS-48/STM-16, STS-192/STM-64 and STS-768/STM-256. At least one
transparency type must be specified when requesting such a signal
type.
Transparency indicates precisely which fields in these overheads
must be delivered unmodified at the other end of the LSP. An
ingress LSR requesting transparency will pass these overhead
fields that must be delivered to the egress LSR without any
change. From the ingress and egress LSRs point of views, these
fields must be seen as unmodified.
E.Mannie & D.Papadimitriou (Editors) 7
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Transparency is not applied at the interfaces with the initiating
and terminating LSRs, but is only applied between intermediate
LSRs. The transparency field is used to request an LSP that
supports the requested transparency type; it may also be used to
setup the transparency process to be applied at each intermediate
LSR.
The different transparency flags are the following:
Flag 1 (bit 1): Section/Regenerator Section layer.
Flag 2 (bit 2): Line/Multiplex Section layer.
Where bit 1 is the low order bit. Other flags are reserved, they
should be set to zero when sent, and should be ignored when
received. A flag is set to one to indicate that the corresponding
transparency is requested.
Intermediate and egress nodes MUST verify that the node itself and
the interfaces on which the LSP will be established can support
the requested transparency. If the requested flags can not be
supported, the receiver node MUST generate a PathErr/NOTIFICATION
message (see Section 2.2/2.3, respectively).
Section/Regenerator Section layer transparency means that the
entire frames must be delivered unmodified. This implies that
pointers cannot be adjusted. When using Section/Regenerator
Section layer transparency all other flags MUST be ignored.
Line/Multiplex Section layer transparency means that the LOH/MSOH
must be delivered unmodified. This implies that pointers cannot be
adjusted.
o) Profile (P): 32 bits
This field is intended to indicate particular capabilities that
must be supported for the LSP, for example monitoring
capabilities.
No standard profile is currently defined and this field SHOULD be
set to zero when transmitted and SHOULD be ignored when received.
In the future TLV based extensions may be created.
2.2. RSVP-TE Details
For RSVP-TE, the SONET/SDH traffic parameters are carried in the
SONET/SDH SENDER_TSPEC and FLOWSPEC objects. The same format is
used both for SENDER_TSPEC object and FLOWSPEC objects. The
content of the objects is defined above in Section 2.1. The
objects have the following class and type for SONET ANSI T1.105
and SDH ITU-T G.707:
SONET/SDH SENDER_TSPEC object: Class = 12, C-Type = 4
SONET/SDH FLOWSPEC object: Class = 9, C-Type = 4
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There is no Adspec associated with the SONET/SDH SENDER_TSPEC.
Either the Adspec is omitted or an int-serv Adspec with the
Default General Characterization Parameters and Guaranteed Service
fragment is used, see [RFC2210].
For a particular sender in a session the contents of the FLOWSPEC
object received in a Resv message SHOULD be identical to the
contents of the SENDER_TSPEC object received in the corresponding
Path message. If the objects do not match, a ResvErr message with
a "Traffic Control Error/Bad Flowspec value" error SHOULD be
generated.
Intermediate and egress nodes MUST verify that the node itself and
the interfaces on which the LSP will be established can support
the requested Signal Type, RCC, NCC, NVC and Multiplier (as
defined in Section 2.1). If the requested value(s) can not be
supported, the receiver node MUST generate a PathErr message with
a "Traffic Control Error/ Service unsupported" indication (see
[RFC2205]).
In addition, if the MT field is received with a zero value, the
node MUST generate a PathErr message with a "Traffic Control
Error/Bad Tspec value" indication (see [RFC2205]).
Intermediate nodes MUST also verify that the node itself and the
interfaces on which the LSP will be established can support the
requested Transparency (as defined in Section 2.1). If the
requested value(s) can not be supported, the receiver node MUST
generate a PathErr message with a "Traffic Control Error/Service
unsupported" indication (see [RFC2205]).
2.3. CR-LDP Details
For CR-LDP, the SONET/SDH traffic parameters are carried in the
SONET/SDH Traffic Parameters TLV. The content of the TLV is
defined above in Section 2.1. The header of the TLV has the
following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|U|F| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The type field for the SONET/SDH Traffic Parameters TLV is:
0x0838.
Intermediate and egress nodes MUST verify that the node itself and
the interfaces on which the LSP will be established can support
the requested Signal Type, RCC, NCC, NVC and Multiplier (as
defined in Section 2.1). If the requested value(s) can not be
supported, the receiver node MUST generate a NOTIFICATION message
with a "Resource Unavailable" status code (see [RFC3212]).
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In addition, if the MT field is received with a zero value, the
node MUST generate a NOTIFICATION message with a "Resource
Unavailable" status code (see [RFC3212]).
Intermediate nodes MUST also verify that the node itself and the
interfaces on which the LSP will be established can support the
requested Transparency (as defined in Section 2.1). If the
requested value(s) can not be supported, the receiver node MUST
generate a NOTIFICATION message with a "Resource Unavailable"
status code (see [RFC3212]).
3. SONET and SDH Labels
SONET and SDH each define a multiplexing structure. Both
structures are trees whose roots are respectively an STS-N or an
STM-N; and whose leaves are the signals that can be transported
via the time-slots and switched between time-slots within an
ingress port and time-slots within an egress port, i.e., a VTx
SPE, an STS-x SPE or a VC-x. A SONET/SDH label will identify the
exact position (i.e., first time-slot) of a particular VTx SPE,
STS-x SPE or VC-x signal in a multiplexing structure. SONET and
SDH labels are carried in the Generalized Label per [RFC3473] and
[RFC3472].
Note that by time-slots we mean the time-slots as they appear
logically and sequentially in the multiplex, not as they appear
after any possible interleaving.
These multiplexing structures will be used as naming trees to
create unique multiplex entry names or labels. The same format of
label is used for SONET and SDH. As explained in [RFC3471], a
label does not identify the "class" to which the label belongs.
This is implicitly determined by the link on which the label is
used.
In case of signal concatenation or multiplication, a list of
labels can appear in the Label field of a Generalized Label.
In case of contiguous concatenation, only one label appears in the
Label field. This unique label is encoded as a single 32 bit label
value (as defined in this Section) of the Generalized Label object
(Class-Num = 16, C-Type = 2)/TLV (0x0825). This label identifies
the lowest time-slot occupied by the contiguously concatenated
signal. By lowest time-slot we mean the one having the lowest
label (value) when compared as integer values, i.e., the time-slot
occupied by the first component signal of the concatenated signal
encountered when descending the tree.
In case of virtual concatenation, the explicit ordered list of all
labels in the concatenation is given. This ordered list of labels
is encoded as a sequence of 32 bit label values (as defined in
this Section) of the Generalized Label object (Class-Num = 16, C-
Type = 2)/TLV (0x0825). Each label indicates the first time-slot
E.Mannie & D.Papadimitriou (Editors) 10
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occupied by a component of the virtually concatenated signal. The
order of the labels must reflect the order of the payloads to
concatenate (not the physical order of time-slots). The above
representation limits virtual concatenation to remain within a
single (component) link; it imposes as such a restriction compared
to the ANSI [T1.105]/ ITU-T [G.707] recommendations. The standard
definition for virtual concatenation allows each virtual
concatenation components to travel over diverse paths. Within
GMPLS, virtual concatenation components must travel over the same
(component) link if they are part of the same LSP. This is due to
the way that labels are bound to a (component) link. Note however,
that the routing of components on different paths is indeed
equivalent to establishing different LSPs, each one having its own
route. Several LSPs can be initiated and terminated between the
same nodes and their corresponding components can then be
associated together (i.e., virtually concatenated).
In case of multiplication (i.e., using the multiplier transform),
the explicit ordered list of all labels that take part in the
Final Signal is given. This ordered list of labels is encoded as a
sequence of 32 bit label values (as defined in this Section) of
the Generalized Label object (Class-Num = 16, C-Type = 2)/TLV
(0x0825). In case of multiplication of virtually concatenated
signals, the explicit ordered list of set of labels that take part
in the Final Signal is given. The first set of labels indicates
the time-slots occupied by the first virtually concatenated
signal, the second set of labels indicates the time-slots occupied
by the second virtually concatenated signal, and so on. The above
representation limits multiplication to remain within a single
(component) link.
The format of the label for SONET and/or SDH TDM-LSR link is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| S | U | K | L | M |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This is an extension of the numbering scheme defined in [G.707]
sections 7.3.7 to 7.3.13, i.e., the (K, L, M) numbering. Note
that the higher order numbering scheme defined in [G.707] sections
7.3.1 to 7.3.6 is not used here.
Each letter indicates a possible branch number starting at the
parent node in the multiplex structure. Branches are considered as
numbered in increasing order, starting from the top of the
multiplexing structure. The numbering starts at 1, zero is used to
indicate a non-significant or ignored field.
When a field is not significant or ignored in a particular context
it MUST be set to zero when transmitted, and MUST be ignored when
received.
E.Mannie & D.Papadimitriou (Editors) 11
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
When a hierarchy of SONET/SDH LSPs is used, a higher order LSP
with a given bandwidth can be used to carry lower order LSPs.
Remember here that a higher order LSP is established through a
SONET/SDH higher order path layer network and a lower order LSP,
through a SONET/SDH lower order path layer network (see also ITU-T
G.803, Section 3 for the corresponding definitions). In this
context, the higher order SONET/SDH LSP behaves as a "virtual
link" with a given bandwidth (e.g., VC-3), it may also be used as
a Forwarding Adjacency. A lower order SONET/SDH LSP can be
established through that higher order LSP. Since a label is local
to a (virtual) link, the highest part of that label (i.e., the S,
U and K fields) is non-significant and is set to zero, i.e., the
label is "0,0,0,L,M". Similarly, if the structure of the lower
order LSP is unknown or not relevant, the lowest part of that
label (i.e., the L and M fields) is non-significant and is set to
zero, i.e., the label is "S,U,K,0,0".
For instance, a VC-3 LSP can be used to carry lower order LSPs.
In that case the labels allocated between the two ends of the VC-3
LSP for the lower order LSPs will have S, U and K set to zero,
i.e., non-significant, while L and M will be used to indicate the
signal allocated in that VC-3.
In case of tunneling such as VC-4 containing VC-3 containing
VC-12/VC-11 where the SUKLM structure is not adequate to represent
the full signal structure, a hierarchical approach must be used,
i.e., per layer network signaling.
The possible values of S, U, K, L and M are defined as follows:
1. S=1->N is the index of a particular STS-3/AUG-1 inside an
STS-N/STM-N multiplex. S is only significant for SONET STS-N
(N>1) and SDH STM-N (N>0). S must be 0 and ignored for STS-1
and STM-0.
2. U=1->3 is the index of a particular STS-1_SPE/VC-3 within an
STS-3/AUG-1. U is only significant for SONET STS-N (N>1) and
SDH STM-N (N>0). U must be 0 and ignored for STS-1 and STM-0.
3. K=1->3 is the index of a particular TUG-3 within a VC-4. K is
only significant for an SDH VC-4 structured in TUG-3s. K must
be 0 and ignored in all other cases.
4. L=1->7 is the index of a particular VT_Group/TUG-2 within an
STS-1_SPE/TUG-3 or VC-3. L must be 0 and ignored in all other
cases.
5. M is the index of a particular VT1.5_SPE/VC-11, VT2_SPE/VC-12
or VT3_SPE within a VT_Group/TUG-2. M=1->2 indicates a specific
VT3 SPE inside the corresponding VT Group, these values MUST
NOT be used for SDH since there is no equivalent of VT3 with
SDH. M=3->5 indicates a specific VT2_SPE/VC-12 inside the
corresponding VT_Group/TUG-2. M=6->9 indicates a specific
VT1.5_SPE/VC-11 inside the corresponding VT_Group/TUG-2.
E.Mannie & D.Papadimitriou (Editors) 12
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Note that a label always has to be interpreted according the
SONET/SDH traffic parameters, i.e., a label by itself does not
allow knowing which signal is being requested (a label is context
sensitive).
The label format defined in this section, referred to as SUKLM,
MUST be used for any SONET/SDH signal requests that are not
transparent i.e., when all Transparency (T) bits defined in
section 2.1 are set to zero. Any transparent STS-1/STM-0/STS-
3*N/STM-N (N=1, 4, 16, 64, 256) signal request MUST use a label
format as defined in [RFC3471].
The S encoding is summarized in the following table:
S SDH SONET
------------------------------------------------
0 other other
1 1st AUG-1 1st STS-3
2 2nd AUG-1 2nd STS-3
3 3rd AUG-1 3rd STS-3
4 4rd AUG-1 4rd STS-3
: : :
N Nth AUG-1 Nth STS-3
The U encoding is summarized in the following table:
U SDH AUG-1 SONET STS-3
-------------------------------------------------
0 other other
1 1st VC-3 1st STS-1 SPE
2 2nd VC-3 2nd STS-1 SPE
3 3rd VC-3 3rd STS-1 SPE
The K encoding is summarized in the following table:
K SDH VC-4
---------------
0 other
1 1st TUG-3
2 2nd TUG-3
3 3rd TUG-3
The L encoding is summarized in the following table:
L SDH TUG-3 SDH VC-3 SONET STS-1 SPE
-------------------------------------------------
0 other other other
1 1st TUG-2 1st TUG-2 1st VTG
2 2nd TUG-2 2nd TUG-2 2nd VTG
3 3rd TUG-2 3rd TUG-2 3rd VTG
4 4th TUG-2 4th TUG-2 4th VTG
5 5th TUG-2 5th TUG-2 5th VTG
6 6th TUG-2 6th TUG-2 6th VTG
E.Mannie & D.Papadimitriou (Editors) 13
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
7 7th TUG-2 7th TUG-2 7th VTG
The M encoding is summarized in the following table:
M SDH TUG-2 SONET VTG
-------------------------------------------------
0 other other
1 - 1st VT3 SPE
2 - 2nd VT3 SPE
3 1st VC-12 1st VT2 SPE
4 2nd VC-12 2nd VT2 SPE
5 3rd VC-12 3rd VT2 SPE
6 1st VC-11 1st VT1.5 SPE
7 2nd VC-11 2nd VT1.5 SPE
8 3rd VC-11 3rd VT1.5 SPE
9 4th VC-11 4th VT1.5 SPE
Examples of labels:
Example 1: the label for the STS-3c_SPE/VC-4 in the Sth STS-3/AUG-
1 is: S>0, U=0, K=0, L=0, M=0.
Example 2: the label for the VC-3 within the Kth-1 TUG-3 within
the VC-4 in the Sth AUG-1 is: S>0, U=0, K>0, L=0, M=0.
Example 3: the label for the Uth-1 STS-1_SPE/VC-3 within the Sth
STS-3/AUG-1 is: S>0, U>0, K=0, L=0, M=0.
Example 4: the label for the VT6/VC-2 in the Lth-1 VT Group/TUG-2
in the Uth-1 STS-1_SPE/VC-3 within the Sth STS-3/AUG-1
is: S>0, U>0, K=0, L>0, M=0.
Example 5: the label for the 3rd VT1.5_SPE/VC-11 in the Lth-1 VT
Group/TUG-2 within the Uth-1 STS-1_SPE/VC-3 within the
Sth STS-3/AUG-1 is: S>0, U>0, K=0, L>0, M=8.
Example 6: the label for the STS-12c SPE/VC-4-4c which uses the
9th STS-3/AUG-1 as its first timeslot is: S=9, U=0,
K=0, L=0, M=0.
In case of contiguous concatenation, the label that is used is the
lowest label (value) of the contiguously concatenated signal as
explained before. The higher part of the label indicates where the
signal starts and the lowest part is not significant.
In case of STM-0/STS-1, the values of S, U and K must be equal to
zero according to the field coding rules. For instance, when
requesting a VC-3 in an STM-0 the label is S=0, U=0, K=0, L=0,
M=0. When requesting a VC-11 in a VC-3 in an STM-0 the label is
S=0, U=0, K=0, L>0, M=6..9.
Note: when a Section/RS or Line/MS transparent STS-1/STM-0/STS-
3*N/STM-N (N=1, 4, 16, 64, 256) signal is requested, the SUKLM
E.Mannie & D.Papadimitriou (Editors) 14
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
label format and encoding is not applicable and the label encoding
MUST follow the rules defined in [RFC3471] Section 3.2.
4. Acknowledgments
Valuable comments and input were received from the CCAMP mailing
list where outstanding discussions took place.
The authors would like to thank Richard Rabbat for its valuable
input that lead to this revision.
5. Security Considerations
This document introduces no new security considerations to either
[RFC3473] or [RFC3472]. GMPLS security is described in section 11
of [RFC3471] and refers to [RFC3209] for RSVP-TE and to [RFC3212]
for CR-LDP.
6. IANA Considerations
Three values have been defined by IANA for this document.
Two RSVP C-Types in registry:
http://www.iana.org/assignments/rsvp-parameters
- A SONET/SDH SENDER_TSPEC object: Class = 12, C-Type = 4 (see
Section 2.2).
- A SONET/SDH FLOWSPEC object: Class = 9, C-Type = 4 (see
Section 2.2).
One LDP TLV Type in registry:
http://www.iana.org/assignments/ldp-namespaces
- A type field for the SONET/SDH Traffic Parameters TLV (see
Section 2.3).
7. References
7.1 Normative References
[G.707] ITU-T Recommendation G.707, "Network Node Interface for
the Synchronous Digital Hierarchy", October 2000.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2205] Braden, R., Zhang, L., Berson, S., Herzog, S., and S.
Jamin, "Resource ReSerVation Protocol (RSVP) -- Version
1 Functional Specification", RFC 2205, September 1997.
[RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
E.Mannie & D.Papadimitriou (Editors) 15
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan,
V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001.
[RFC3212] Jamoussi, B., Andersson, L., Callon, R., Dantu, R.,
Wu, L., Doolan, P., Worster, T., Feldman, N.,
Fredette, A., Girish, M., Gray, E., Heinanen, J.,
Kilty, T., and A. Malis, "Constraint-Based LSP Setup
using LDP", RFC 3212, January 2002.
[RFC3471] Berger, L., "Generalized Multi-Protocol Label
Switching (MPLS) Signaling Functional Description",
RFC 3471, January 2003.
[RFC3472] Ashwood-Smith, P. and L. Berger, "Generalized Multi-
Protocol Label Switching (MPLS) Signaling -
Constraint-based Routed Label Distribution Protocol
(CR-LDP) Extensions", RFC 3472, January 2003.
[RFC3473] Berger, L., "Generalized Multi-Protocol Label
Switching (MPLS) Signaling - Resource ReserVation
Protocol Traffic Engineering (RSVP-TE) Extensions",
RFC 3473, January 2003.
[RFC3945] Mannie, E., Ed., "Generalized Multiprotocol Label
Switching (GMPLS) Architecture", RFC 3945, October
2004.
[T1.105] "Synchronous Optical Network (SONET): Basic
Description Including Multiplex Structure, Rates, and
Formats", ANSI T1.105, October 2000.
E.Mannie & D.Papadimitriou (Editors) 16
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Appendix 1 - Signal Type Values Extension for VC-3
This appendix defines the following optional additional Signal
Type value for the Signal Type field of section 2.1:
Value Type
----- ---------------------
20 "VC-3 via AU-3 at the end"
According to the ITU-T [G.707] recommendation a VC-3 in the TU-
3/TUG-3/VC-4/AU-4 branch of the SDH multiplex cannot be structured
in TUG-2s, however a VC-3 in the AU-3 branch can be. In addition,
a VC-3 could be switched between the two branches if required.
A VC-3 circuit could be terminated on an ingress interface of an
LSR (e.g. forming a VC-3 forwarding adjacency). This LSR could
then want to demultiplex this VC-3 and switch internal low order
LSPs. For implementation reasons, this could be only possible if
the LSR receives the VC-3 in the AU-3 branch. E.g. for an LSR not
able to switch internally from a TU-3 branch to an AU-3 branch on
its incoming interface before demultiplexing and then switching
the content with its switch fabric.
In that case it is useful to indicate that the VC-3 LSP must be
terminated at the end in the AU-3 branch instead of the TU-3
branch.
This is achieved by using the "VC-3 via AU-3 at the end" signal
type. This information can be used, for instance, by the
penultimate LSR to switch an incoming VC-3 received in any branch
to the AU-3 branch on the outgoing interface to the destination
LSR.
The "VC-3 via AU-3 at the end" signal type does not imply that the
VC-3 must be switched via the AU-3 branch at some other places in
the network. The VC-3 signal type just indicates that a VC-3 in
any branch is suitable.
E.Mannie & D.Papadimitriou (Editors) 17
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Annex 1 - Examples
This annex defines examples of SONET and SDH signal coding. Their
objective is to help the reader to understand how works the traffic
parameter coding and not to give examples of typical SONET or SDH
signals.
As stated above, signal types are Elementary Signals to which
successive concatenation, multiplication and transparency
transforms can be applied to obtain Final Signals.
1. A VC-4 signal is formed by the application of RCC with value
0, NCC with value 0, NVC with value 0, MT with value 1 and T
with value 0 to a VC-4 Elementary Signal.
2. A VC-4-7v signal is formed by the application of RCC with value
0, NCC with value 0, NVC with value 7 (virtual concatenation of
7 components), MT with value 1 and T with value 0 to a VC-4
Elementary Signal.
3. A VC-4-16c signal is formed by the application of RCC with
value 1 (standard contiguous concatenation), NCC with value 16,
NVC with value 0, MT with value 1 and T with value 0 to a VC-4
Elementary Signal.
4. An STM-16 signal with Multiplex Section layer transparency is
formed by the application of RCC with value 0, NCC with value
0, NVC with value 0, MT with value 1 and T with flag 2 to an
STM-16 Elementary Signal.
5. An STM-4 signal with Multiplex Section layer transparency is
formed by the application of RCC with value 0, NCC with value
0, NVC with value 0, MT with value 1 and T with flag 2 applied
to an STM-4 Elementary Signal.
6. An STM-256 signal with Multiplex Section layer transparency is
formed by the application of RCC with value 0, NCC with value
0, NVC with value 0, MT with value 1 and T with flag 2 applied
to an STM-256 Elementary Signal.
7. An STS-1 SPE signal is formed by the application of RCC with
value 0, NCC with value 0, NVC with value 0, MT with value 1
and T with value 0 to an STS-1 SPE Elementary Signal.
8. An STS-3c SPE signal is formed by the application of RCC with
value 1 (standard contiguous concatenation), NCC with value 1,
NVC with value 0, MT with value 1 and T with value 0 to an STS-
3c SPE Elementary Signal.
9. An STS-48c SPE signal is formed by the application of RCC with
value 1 (standard contiguous concatenation), NCC with value 16,
NVC with value 0, MT with value 1 and T with value 0 to an STS-
3c SPE Elementary Signal.
E.Mannie & D.Papadimitriou (Editors) 18
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
10.An STS-1-3v SPE signal is formed by the application of RCC
with value 0, NVC with value 3 (virtual concatenation of 3
components), MT with value 1 and T with value 0 to an STS-1 SPE
Elementary Signal.
11.An STS-3c-9v SPE signal is formed by the application of RCC
with value 1, NCC with value 1, NVC with value 9 (virtual
concatenation of 9 STS-3c), MT with value 1 and T with value 0
to an STS-3c SPE Elementary Signal.
12.An STS-12 signal with Section layer (full) transparency is
formed by the application of RCC with value 0, NCC with value
0, NVC with value 0, MT with value 1 and T with flag 1 to an
STS-12 Elementary Signal.
13.A 3 x STS-768c SPE signal is formed by the application of RCC
with value 1, NCC with value 256, NVC with value 0, MT with
value 3, and T with value 0 to an STS-3c SPE Elementary Signal.
14.
A 5 x VC-4-13v composed signal is formed by the application of
RCC with value 0, NVC with value 13, MT with value 5 and T with
value 0 to a VC-4 Elementary Signal.
The encoding of these examples is summarized in the following
table:
Signal ST RCC NCC NVC MT T
--------------------------------------------------------
VC-4 6 0 0 0 1 0
VC-4-7v 6 0 0 7 1 0
VC-4-16c 6 1 16 0 1 0
STM-16 MS transparent 10 0 0 0 1 2
STM-4 MS transparent 9 0 0 0 1 2
STM-256 MS transparent 12 0 0 0 1 2
STS-1 SPE 5 0 0 0 1 0
STS-3c SPE 6 1 1 0 1 0
STS-48c SPE 6 1 16 0 1 0
STS-1-3v SPE 5 0 0 3 1 0
STS-3c-9v SPE 6 1 1 9 1 0
STS-12 Section transparent 9 0 0 0 1 1
3 x STS-768c SPE 6 1 256 0 3 0
5 x VC-4-13v 6 0 0 13 5 0
Contributors
Contributors are listed by alphabetical order:
Stefan Ansorge (Alcatel)
Lorenzstrasse 10
70435 Stuttgart, Germany
EMail: stefan.ansorge@alcatel.de
Peter Ashwood-Smith (Nortel)
PO. Box 3511 Station C,
E.Mannie & D.Papadimitriou (Editors) 19
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Ottawa, ON K1Y 4H7, Canada
EMail:petera@nortelnetworks.com
Ayan Banerjee (Calient)
5853 Rue Ferrari
San Jose, CA 95138, USA
EMail: abanerjee@calient.net
Lou Berger (Movaz)
7926 Jones Branch Drive
McLean, VA 22102, USA
EMail: lberger@movaz.com
Greg Bernstein (Ciena)
10480 Ridgeview Court
Cupertino, CA 94014, USA
EMail: greg@ciena.com
Angela Chiu (Celion)
One Sheila Drive, Suite 2
Tinton Falls, NJ 07724-2658
EMail: angela.chiu@celion.com
John Drake (Calient)
5853 Rue Ferrari
San Jose, CA 95138, USA
EMail: jdrake@calient.net
Yanhe Fan (Axiowave)
100 Nickerson Road
Marlborough, MA 01752, USA
EMail: yfan@axiowave.com
Michele Fontana (Alcatel)
Via Trento 30,
I-20059 Vimercate, Italy
EMail: michele.fontana@alcatel.it
Gert Grammel (Alcatel)
Lorenzstrasse, 10
70435 Stuttgart, Germany
EMail: gert.grammel@alcatel.de
Juergen Heiles (Siemens)
Hofmannstr. 51
D-81379 Munich, Germany
EMail: juergen.heiles@siemens.com
Suresh Katukam (Cisco)
1450 N. McDowell Blvd,
Petaluma, CA 94954-6515, USA
EMail: suresh.katukam@cisco.com
Kireeti Kompella (Juniper)
E.Mannie & D.Papadimitriou (Editors) 20
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
1194 N. Mathilda Ave.
Sunnyvale, CA 94089, USA
EMail: kireeti@juniper.net
Jonathan P. Lang (Calient)
25 Castilian
Goleta, CA 93117, USA
EMail: jplang@calient.net
Fong Liaw (Solas Research)
EMail: fongliaw@yahoo.com
Zhi-Wei Lin (Lucent)
101 Crawfords Corner Rd
Holmdel, NJ 07733-3030, USA
EMail: zwlin@lucent.com
Ben Mack-Crane (Tellabs)
EMail: ben.mack-crane@tellabs.com
Dimitrios Pendarakis (Tellium)
2 Crescent Place, P.O. Box 901
Oceanport, NJ 07757-0901, USA
EMail: dpendarakis@tellium.com
Mike Raftelis (White Rock)
18111 Preston Road
Dallas, TX 75252, USA
Bala Rajagopalan (Tellium)
2 Crescent Place, P.O. Box 901
Oceanport, NJ 07757-0901, USA
EMail: braja@tellium.com
Yakov Rekhter (Juniper)
1194 N. Mathilda Ave.
Sunnyvale, CA 94089, USA
EMail: yakov@juniper.net
Debanjan Saha (Tellium)
2 Crescent Place, P.O. Box 901
Oceanport, NJ 07757-0901, USA
EMail: dsaha@tellium.com
Vishal Sharma (Metanoia)
335 Elan Village Lane
San Jose, CA 95134, USA
EMail: vsharma87@yahoo.com
George Swallow (Cisco)
250 Apollo Drive
Chelmsford, MA 01824, USA
EMail: swallow@cisco.com
E.Mannie & D.Papadimitriou (Editors) 21
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Z. Bo Tang (Tellium)
2 Crescent Place, P.O. Box 901
Oceanport, NJ 07757-0901, USA
EMail: btang@tellium.com
Eve Varma (Lucent)
101 Crawfords Corner Rd
Holmdel, NJ 07733-3030, USA
EMail: evarma@lucent.com
Yangguang Xu (Lucent)
21-2A41, 1600 Osgood Street
North Andover, MA 01845, USA
EMail: xuyg@lucent.com
Authors' Addresses
Eric Mannie (Consultant)
Avenue de la Folle Chanson, 2
B-1050 Brussels, Belgium
Phone: +32 2 648-5023
Mobile: +32 (0)495-221775
EMail: eric_mannie@hotmail.com
Dimitri Papadimitriou (Alcatel)
Francis Wellesplein 1,
B-2018 Antwerpen, Belgium
Phone: +32 3 240-8491
EMail: dimitri.papadimitriou@alcatel.be
E.Mannie & D.Papadimitriou (Editors) 22
draft-ietf-ccamp-rfc3946bis-01.txt December 2005
Full Copyright Statement
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This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
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E.Mannie & D.Papadimitriou (Editors) 23
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