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RE: Moving right along ... Switching Type
Following the discussion on the Switching Type and looking on the proposed G.709 extensions for GMPLS I would like to get some feedback on the examples shown below.
How to handle the examples concerning label request and returned label is important for my understanding of GMPLS.
The examples are based on G.709 ODUs. A ODU can be transported via WDM systems or using TDM in a higher bit rate ODU. So we can have a mixture of both methods.
Juergen
Example 1:
Two network elements A and B with ODU1 cross-connect are interconnected by two types of signals.
- a four channel WDM OTM-4.1 interface with 4 optical channels each carrying an OTU1/ODU1
- a single channel OTM-1.2 with one optical channel carrying a OTU2/ODU2 and 4 ODU1 multiplexed into the ODU2.
----------------- ----------------
NE A + + NE B
+ +
ODU1 ----- + + ----- ODU1
1 o---+ + + OTM-4.1 + + +---o 1
2 o---+ w + + 4xOCh with OTU1/ODU1 + + W +---o 2
+ D +--------------------------------+ D +
3 o---+ M + + + + M +---o 3
4 o---+ + + + + +---o 4
----- + + -----
+ +
ODU1 ----- + + ----- ODU1
5 o---+ + + OTM-0.2 + + +---o 5
6 o---+ T + + 1xOCh with OTU2/ODU2 + + T +---o 6
+ D +--------------------------------+ D +
7 o---+ M + + with 4 ODU1 + + M +---o 7
8 o---+ + + + + +---o 8
----- + + -----
+ +
----------------- -----------------
Now setting up a ODU1 connection between A and B. 8 ODU1 connections are available, 4 using WDM technology and 4 using TDM technology.
For the connection itself I don't care which of the 8 is used and I don't care about the specific technology.
How does the label request from NE a to NE B look like?
- the LSP encoding type is "G.709 digital path layer"
- the signal type is ODU1
- but what is the switching type "TDM" or "Lambda"? Both are available.
Furthermore what kind of label is returned by NE B to NE A?
- for ODU 5 to 8 a "G.709 digital path layer label" with signal type ODU1 and a indication of the time slot within the ODU2
- but how about ODU1 to 4, a G.709 OCh signal type with the indication of the wavelength is not correct.
or is each ODU 1 to 4 seen as individual link?
Example 2:
NE A and NE C that provide ODU1 cross-connections are interconnected via NE B that is not GMPLS aware and that performs a conversion between WDM and TDM multiplexing.
- between NE A and NE B a four channel WDM OTM-4.1 signal is used with 4 optical channels, each carrying a OTU1/ODU1.
- between NE B and NE C a single channel OTM-0.2 signal is used with one optical channel carrying a OTU2/ODU2 with 4 ODU1 multiplexed into the ODU2.
------------- ---------------- -------------
NE A + + NE B + + NE C
+ + ODU1 + +
ODU1 ----- + + ----- ----- + + ----- ODU1
1 o--+ + + OTM-4.1 + + +--+ + + OTM-0.2 + + +--o 1
2 o--+ w + + 4xOCh with + + W +--+ T + + 1xOCh with + + T +--o 2
+ D +----------------+ D + + D +-----------------+ D +
3 o--+ M + + OTU1/ODU1 + + M +--+ M + + OTU1/ODU1 + + M +--o 3
4 o--+ + + + + +--+ + + with 4 ODU1 + + +--o 4
----- + + ----- ----- + + -----
+ + + +
------------- ---------------- -------------
Again what is the switching type of the label request from NE A to NE C (TDM or Lambda)?
And what is the returned label from NE C to NE A?