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AW: [T1X1.5] arbitrary contiguous concatenation question
Eric,
as arbitrary contiguous concatenation is not defined by ITU or T1X1 and only mentioned in this document it should be clarified here.
If you look on a STS-3c-SPE contiguous concatenated signal you notice that it is not really contiguous when it is combined with other STS-SPE signals in higher bandwidth STS-N signal. This is due to the two stage multiplex process defined for SONET (historical reasons). In a first step a STS-3 is gnerated by byte interleaving 3 STS-1. In a second step a STS-3x is generated by byte interleaving x STS-3.
Some examples:
A STS-3c-SPE in a STS-3:
The STS-3 has the STS-1 time slots 1,2 and 3.
The STS-3c-SPE uses the time slots 1,2 and 3. -> contiguous
A STS-3c-SPE in a STS-12:
The STS-12 has the STS-1 time slots 1 to 12.
The STS-3c-SPE can use the time slots
1, 5 and 9
2, 6 and 10
3, 7 and 11
4, 8 and 12
-> not contiguous
A STS-12c-SPE in a STS-12:
The STS-12 has the STS-1 time slots 1 to 12.
The STS-12c-SPE uses the time slots 1 to 12. -> contiguous
A STS-12c-SPE in a STS-192:
The STS-192 has the STS-1 time slots 1 to 192
The STS-12c-SPE can use the time slots
1,2,3,4, 65,66,67,68, 129,130,131,132
5,6,7,8, 69,70,71,72, 133,134,135,136
....
61,62,53,64, 125,126,127,128, 189,190,191,192
-> not contiguous
From a STS-1 time slot view the STS-Nc-SPE doesn't use contiguous time slots.
Only fro ma STS-3 time slot view a STS-Nc-SPE uses contiguous time slots.
A STS-12c-SPE in a STS-192:
The STS-192 has the STS-3 time slots 1 to 64
The STS-12c-SPE can use the time slots
1,2,3,4,
5,6,7,8,
....
61,62,53,64,
-> contiguous
For arbitrary contiguous concatenation which can have any number of concetenated STS-1 and any starting time slot we have to define which time sltos are used, contiguous STS-1 or STS-3time slots? Should arbitrary contiguous cocnatenation of STS-1s use contiguous STS-1 time slots and arbitrary concatenation of STS-3c contiguous STS-3 timeslots in order to aline with arbitrary concatenatin of VC-4? This has to be defeind in order to achieve interworking as currently only hte number of concateanted signals and the starting time slot is defined for arbitrary contiguous concatenation. Another solution as Maarten mentioned is to list each individual time slot as for virtual concatenation.
This shows me again that it is very difficult to define support for proprietary features without having detailed information about them. You assume that you understand the feature, but as soon as you go into the details later on you detect problems.
Regards
Juergen
> -----Ursprüngliche Nachricht-----
> Von: Mannie, Eric [mailto:Eric.Mannie@ebone.com]
> Gesendet: Mittwoch, 25. Juli 2001 14:56
> An: 'Heiles Juergen'; 'Maarten Vissers'; ccamp
> Cc: t1x1.5; q11/15
> Betreff: ARE: [T1X1.5] arbitrary contiguous concatenation question
>
>
> Hello Juergen and Maarten,
>
> I don't understand the relationship between
> draft-ietf-ccamp-gmpls-sonet-sdh-01.txt and the problem that
> you are talking
> about.
>
> In addition, the IETF is not specifying any SDH/SONET
> interoperability (Not
> at all in the GMPLS scope).
>
> Also, I am not sure to understand why the abstract (B, A)
> notation of G.707
> (used to have a clearer specification, and not used
> (transported) in any
> protocol as far as I know) could imply that contiguous
> time-slots are not
> contiguous anymore ?
>
> The "Arbitrary" concatenation that you are speaking about is
> a contiguous
> concatenation, time-slots are physically contiguous. I don't
> understand the
> relevance of the SDH (B, A) notation in relationship with SONET in the
> context of the IETF. Anyway, contiguous time-slots will stay
> physically
> contiguous even if you see an issue with the SDH G.707 (B, A) notation
> applied to SONET.
>
> Also, "flexible arbitrary concatenation" (whatever it is -
> everybody seems
> to have a different understanding) is not part of
> draft-ietf-ccamp-gmpls-sonet-sdh-01.txt.
>
> I guess also that this discussion is relevant for the ITU-T
> and/or T1X1, not
> for the ccamp mailing list (of the IETF).
>
> Kind regards,
>
> Eric
>
> -----Original Message-----
> From: Heiles Juergen [mailto:Juergen.Heiles@icn.siemens.de]
> Sent: Tuesday, July 24, 2001 4:28 PM
> To: 'Maarten Vissers'; ccamp
> Cc: t1x1.5; q11/15
> Subject: AW: [T1X1.5] arbitrary contiguous concatenation question
>
>
> Maarten,
>
> good point. Lets hear what the supporters of arbitrary
> concatenation have to
> say.
>
> Juergen
>
> > -----Ursprüngliche Nachricht-----
> > Von: Maarten Vissers [mailto:mvissers@lucent.com]
> > Gesendet: Dienstag, 10. Juli 2001 11:14
> > An: ccamp
> > Cc: t1x1.5; q11/15
> > Betreff: [T1X1.5] arbitrary contiguous concatenation question
> >
> >
> > All,
> >
> > draft-ietf-ccamp-gmpls-sonet-sdh-01.txt defines signalling
> > support for arbitrary
> > contiguous concatenation in appendix 3. Looking a bit more
> > into this arbitrary
> > concatenation from the transport plane, I came across a
> > question with respect to
> > the definition of "contiguous STS-1/AU-3 timeslots". Let me
> > introduce this
> > question:
> >
> > Figure 7-25/G.707 (10/2000) lists the AU-3 numbering (within
> > an STM-4) as
> > follows
> >
> > Time 111
> > Slot 123456789012123456789
> >
> > B 123412341234123412341...
> > A 111122223333111122223...
> >
> > AU-3 timeslots have a TimeSlot number and a (B,A) number,
> > with TS1 associated
> > with (1,1) and TS12 associated with (4,3).
> >
> > Note - the figure in the pre-published version of G.707
> > doesn't show the timeslot numbering in a correct manner.
> >
> > and the AU-4 numbering is as follows (figure 7-24/G.707)
> >
> > Time
> > Slot 123412341234123412341
> >
> > B 123412341234123412341...
> > A 000000000000000000000...
> >
> > An AU-4 [STS-3c] is as such essentially a "non-contiguous"
> > concatenation of
> > AU-3s [STS-1s]; i.e. every 4th AU-3/STS-1 is use; e.g. AU-4
> > (2,0) uses AU-3
> > timeslots 2,6,10 [i.e. (2,1), (2,2), (2,3)].
> >
> >
> > If we define STS-1 contiguous concatenation, which timeslots
> > are then used for
> > e.g. a STS-1-3c:
> > i) timeslots (1,1),(2,1) and (3,1) [TS1,TS2,TS3], or
> > ii) timeslots (1,1), (1,2) and (1,3) [TS1,TS5,TS9]
> >
> > Similarly, for the case of a STS-1-6c do we use:
> > i) (1,1), (2,1), (3,1), (4,1), (1,2) and (2,2)
> > [TS1,TS2,TS3,TS4,TS5,TS6] or
> > ii) (1,1), (2,1), (1,2), (2,2), (1,3) and (2,3)
> > [TS1,TS2,TS5,TS6,TS9,TS10]
> >
> >
> > And which timeslots do we use for e.g. a STS-1-5c?
> >
> >
> > If this detail is not specified, interworking is not possible
> > unless we include
> > the list of timeslots as we do with virtual concatenation
> > (and as discussed for
> > flexible arbitrary concatenation).
> >
> >
> > Regards,
> >
> > Maarten
> >
>