Re: Doubt in ccamp-gmpls-sdh-sonet-01.txt

[Maarten Vissers <mvissers@lucent.com>]

Manoj,

manoj juneja wrote:
> 
> Hi All,
> 
>         In draft ccamp-gmpls-sonet-sdh-01.txt, concept of hierarchical
> sonet/sdh LSPs has been described. It mentions that the higher order
> sdh/sonet LSP behaves as a virtual link with a given bandwidth (e.g. VC
> -3). A lower order SDH/SONET LSP can be established through that higher
> LSP. For e.g. VC-3 LSP can be advertised as a FA. In this case all
> labels allocated between two ends of that LSP 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 my opinion in all cases LOVC/VT connections will have S and U (and when
transported in a VC-3/STS-1 also K) set to zero. This implies that examples 2 to
5 in section 3 of the document present non-existing cases. Also example 1 is not
correct. Are we misleading the reader here?

> Please clarify how the higher order LSP will be established ? 

For a HO-VC-3 link connection the following values are applicable (case of e.g.
VC-3 (4,1) in a STM-4):
    
    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 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
   |  ST=5         |      RCC=0    |              NCC=0            | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
   |              NVC=0            |        Multiplier (MT)=0      | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
   |                       Transparency (T)=0                      | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
 
    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=4             |   U=1 |   K=0 |   L=0 |   M=0 | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 

The above only results in the allocation of VC-3 link conneciton number (4,1) in
e.g. a STM-4 to a VC-3 connection. There might be many more VC-3 link
connections and VC-3 matrix connections present in the total VC-3 path between
the VC-3 path termination functions.



> Once the higher order LSP gets established, the lower order signals 
> within higher order signals will also gets allocated. 

Once two VC-3 path terminations are interconnected via a series of VC-3 matrix
connections and VC-3 link connections, there is a LOVC link established. The
provisioning of the TU pointer processors at both VC-3 path termination
endpoints determines now the LOVC link's substructure (i.e. TU-11, TU-12, TU-2
structure).

Three cases: 
1) the LOVC link ends at a fabric at both sides:
	Now there are no LOVC signals going over any of the LOVC
	link connections in the LOVC link.

2) the LOVC link ends at VC-11/12/2 termination functions at one side and a
fabric at the other side:
	Now LOVC signals are generated at one side and inserted into
	the LOVC link connections in the LOVC link. At the other end
	these signals end up at the ingress of a Fabric, where the transport
	stops until the moment the matrix connections are provisioned
	in the fabric. In the other direction, the fabric generates LOVC UNEQ
	signals, which will cause LOVC-UNEQ alarms to be raised (unless
	alarm reporting is disabled).

3) the LOVC link ends at VC-11/12/2 termination functions at both sides:
	Now LOVC signals are generated at both sides and inserted into
	the LOVC link connections in the LOVC link. The creation of the 
	VC-3 path also has created the set of LOVC paths. Assumption is
	that both endpoints have the same set of LOVC path termination
	points; otherwise there will be TU-LOP alarms.


> Then how can I again allocate the lower order signals ?

This is only important in cases 1 and 2. Here you have no lower order signals
flowing, you have only LOVC link connections created which are waiting for a
LOVC signal to be transported over it.

Assume you want to transport a VC-11 over VC-11 link connection number (3,1),
then you will see the following request
    
    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 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
   |  ST=1         |      RCC=0    |              NCC=0            | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
   |              NVC=0            |        Multiplier (MT)=0      | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
   |                       Transparency (T)=0                      | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
    
 
    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=0             |   U=0 |   K=0 |   L=4 |   M=7 | 
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 
 



Regards,

Maarten
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