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RE: Representation of VC-3 in STM-0 in {SUKLM} format
Manjo,
indeed the STM-0 case is not covered in the current definition. This is one of the reasons for my proposed changes to the label definition I did sent out as a last call comment. SONET and SDH have similar structures and using different {SUKLM} numbering schemes results in confusion and problems like this that something is missing for one hierarchy.
I haven't seen a final decision concerning the {SUKLM} scheme so I have attached my proposal again.
Juergen
The format of the label for SDH and/or SONET 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
For SDH, this is an extension of the numbering scheme defined in
G.707 section 7.3, i.e. the (K, L, M) numbering. For SONET, the same
signaling scheme is used in order to provide easy interworking between
SDH and SONET signaling. For the S field a STS-3 group, which
corresponds with the SDH AUG-1 level is introduce. The U field indicates
the position of the STS-3c-SPE or STS-1-SPE within the STS-3 group.
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 field.
When a field is not significant in a particular context it MUST be
set to zero when transmitted, and MUST be ignored when received.
When hierarchical SDH/SONET LSPs are used, an LSP with a given
bandwidth can be used to tunnel lower order LSPs. The higher
order SDH/SONET 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 SDH/SONET LSP can be established through
that higher order LSP. Since a label is local to a (virtual) link,
the highest part of that label is non-significant and is set to
zero.
For instance, a VC-3 LSP can be advertised as a forwarding
adjacency. In that case the labels allocated between the two ends
of that LSP (i.e. for that "link") 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.
1. S is the index of a particular AUG-1/STS-3 group. S=1->N
indicates a specific AUG-1/STS-3 group inside an STM-N/STS-3xN
multiplex. For example, S=1 indicates the first AUG-1/STS-3 group,
and S=N indicates the last AUG-1/STS-3 group of this multiplex.
S is not significant for STM-0/STS-1.
2. U indicates a specific VC/STS-SPE inside a given AUG-1/STS-3
group or STM-0/STS-1. U=1 indicates a single VC-4/STS-3c-SPE in a
AUG-1/STS-3 group or the single VC-3/STS-1-SPE in a STM-0/STS-1, while U=2->4
indicates a specific VC-3/STS-1-SPE inside the given AUG-1/STS-3
group.
3. K is only significant for VC-4/STS-3c and must be ignored for
higher order VC-3/STS-1-SPE. For SDH it indicates a specific branch of a VC-4.
K=1 indicates that the VC-4 is not further subdivided and
contains a C-4. K=2->4 indicates a specific TUG-3 inside the VC-4.
For a SONET STS-3c-SPE it is fixed to K=1 as SONET doesn't support
substructured STS-3c-SPE.
4. L indicates a specific branch of a TUG-3, VC-3 or STS-1 SPE.
It is not significant for an unstructured VC-4/STS-3c-SPE. L=1
indicates that the TUG-3/VC-3/STS-1 SPE is not further
subdivided and contains a VC-3/C-3 in SDH or the equivalent in
SONET. L=2->8 indicates a specific TUG-2/VT Group inside the
corresponding higher order signal.
5. M indicates a specific branch of a TUG-2/VT Group. It is not
significant for an unstructured VC-4, STS-3c-SPE, TUG-3, VC-3 or STS-1 SPE.
M=1 indicates that the TUG-2/VT Group is not further subdivided
and contains a VC-2/VT-6 SPE. M=2->3 indicates a specific VT-3
inside the corresponding VT Group, these values MUST NOT be used
for SDH since there is no equivalent of VT-3 with SDH. M=4->6
indicates a specific VC-12/VT-2 SPE inside the corresponding
TUG-2/VT Group. M=7->10 indicates a specific VC-11/VT-1.5 SPE
inside the corresponding TUG-2/VT Group. Note that M=0 denotes
an unstructured VC-4, VC-3 or STS-1 SPE (easy for debugging).
The M encoding is summarized in the following table:
M SDH SONET
----------------------------------------------------------
0 unstructured VC-4/VC-3 unstructured STS-1 SPE
1 VC-2 VT-6
2 - 1st VT-3
3 - 2nd VT-3
4 1st VC-12 1st VT-2
5 2nd VC-12 2nd VT-2
6 3rd VC-12 3rd VT-2
7 1st VC-11 1st VT-1.5
8 2nd VC-11 2nd VT-1.5
9 3rd VC-11 3rd VT-1.5
10 4th VC-11 4th VT-1.5
In case of contiguous concatenation, the label that is used is the
lowest label 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. For instance, when
requesting an VC-4-16c the label is S>0, U=0, K=0, L=0, M=0.
Examples of labels:
Example 1: S>0, U=1, K=1, L=0, M=0
Denotes the unstructured VC-4/STS-3c-SPE of the Sth AUG-1/STS-3 group.
Example 2: S>0, U=1, K>1, L=1, M=0
Denotes the unstructured VC-3 of the Kth-1 TUG-3 of the Sth AUG-1.
Example 3: S>0, U>1, K=0, L=1, M=0
Denotes the Uth unstructured VC-3/STS-1 SPE of the Sth AUG-1/STS-3 group.
Example 4: S>0, U>1, K=0, L>1, M=1
Denotes the VC-2/VT-6 in the Lth-1 TUG2/VT Group in the Uth VC-3/STS-1 SPE of the Sth AUG-1/STS-3 group.
Example 5: S>0, U>1, K=0, L>1, M=9
Denotes the 3rd VC-11/VT-1.5 in the Lth-1 TUG2/VT Group in the Uth VC-3/STS-1 SPE of the Sth AUG-1/STS-3 group.
Example 6: S>0, U=1, K>1, L>1, M=5
Denotes the 2nd VC-12 in the Lth-1 TUG2 in the Kth TUG3 in the VC-4 of the Sth AUG-1.
> -----Original Message-----
> From: manoj juneja [mailto:manojkumarjuneja@hotmail.com]
> Sent: Tuesday, November 20, 2001 1:49 AM
> To: ccamp@ops.ietf.org
> Subject: Representation of VC-3 in STM-0 in {SUKLM} format
>
>
> Hi All,
> If I have to allocate VC-3 on a STM-0 link then how to
> represent it in {SUKLM}? As per gmpls-sdh-sonet draft, S is the index
> of particular AUG-1 and can take values from 1 -> N. but there is no
> AUG-1 in STM-0.
>
> Regards,
> manoj.
>
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