Re: Need for hierarchical SONET/SDH LSPs.

[Maarten Vissers <mvissers@lucent.com>]

Vinay,

I assume that the signal on the fiber between A and B is an OC-12/STM-4 optical
signal (carrying the STM-4/STS-12 signal) and on the fiber between B and C it is
a OC-48/STM-16 optical signal (carrying the STM-16/STS-48 signal). Nodes A, B
and C will have HOVC/STS switch fabrics which may support a subset of
VC-3/STS-1, VC-4/STS-3c, VC-4-4c/STS-12c, VC-4-16c/STS-48c swtiching; e.g. A
node may support VC-4 switching, where as B and C nodes may support VC-4 and
VC-4-4c switching.

If all nodes support VC-4/STS-3c switching (and they typically do) and the
STM-N/STS-N links between the nodes also support VC-4/STS-3c link connections
(also typically the case), then you can setup a VC-4/STS-3c connection between
nodes A and C. The VC-4/STS-3c payload is totally unimportant for this
connection; any payload can be present.

Regards,

Maarten

> Vinay Vernekar wrote:
> 
> Hi,
> Can I have a SONET/SDH LSP that passes through a SONET ADM as its transit
> LSR??
> Consider a situation as shown below -
> 
> A---------------B---------------C
> 
> The link A-B is a STS-12 link, B does a byte-interleaved multiplexing of 4
> STS-12 and forms a STS-48, thus B-C is STS-48.
> Can a LSP for unstructured VC-4 be setup with A as ingress, B as transit and C
> as the egress??
> As per the draft "Framework for GMPLS based control of SONET/SDH networks" the
> frames are not labeled instead it is the flow that is being labelled. It also
> mentions that tunnels should be used when switching from a different signal
> level i.e VC-12 to VC-4.
> With this in mind, I would assume that a LSP as mentioned should be possible,
> because the signal type remains same i.e VC-4 even the frames get interleaved
> from STS-12 to STS-48.
> Please correct me if I am wrong.
> 
> Thanks in advance.
> Regards
> Vinay
> 
> 
>                            Name: Wipro_Disclaimer.txt
>    Wipro_Disclaimer.txt    Type: Plain Text (text/plain)
>                        Encoding: 7bit
begin:vcard 
n:Vissers;Maarten
tel;cell:+31 62 061 3945
tel;fax:+31 35 687 5976
tel;home:+31 35 526 5463
tel;work:+31 35 687 4270
x-mozilla-html:FALSE
org:Optical Network Group;Lucent Technologies Nederland
version:2.1
email;internet:mvissers@lucent.com
title:Consulting Member of Technical Staff
adr;quoted-printable:;;Botterstraat 45=0D=0A=0D=0A;1271 XL Huizen;;;The Netherlands
fn:Maarten Vissers
end:vcard