RE: Question about logical link in Link bundling

["Fong, Man Wing" <MFong@WhiteRockNetworks.com>]

Maarten, 

Very good point and description. The last case that you describe using VC
would be a good alternative to support the bandwidth on demand. Now that the
inverse muxing capability is being transferred from the router to the
transport NEs. In this case, (Debanjan, you're right), the user would use an
OC-12c interface on a router instead of the channelized OC-12 interface to
save cost for this application (BOD). 

Thanks,
Man Wing

 -----Original Message-----
From: 	Maarten Vissers [mailto:mvissers@lucent.com] 
Sent:	Wednesday, May 09, 2001 5:06 AM
To:	Debanjan Saha
Cc:	'Fong, Man Wing'; Bala Rajagopalan; mpls@UU.NET; 'Kireeti Kompella';
ccamp@ops.ietf.org
Subject:	Re: Question about logical link in Link bundling

 << File: Card for Maarten Vissers >> Debanjan,

Just a thought... those 12 DS3s terminating on the same router (and
providing access to 12 MPLS links) may terminate at the other ends on 12
different routers. With one physical (OC12) interface you have now made
(with the help of the transport network) connections with 12 other
routers. Very cost effective... 

Ofcourse you don't need a DS3 to be present in the STS1 is the router at
the other end of the transport network has a EC1 of (channelised) OC-N
interface. In this case you may deploy direct mapping of MPLS into STS1
payload (via PPP/HDLC or the new GFP encapsulation).

One further cost reduction step (for the case there are e.g. only 5
other routers connected) is to use STS1 virtual concatenation with GFP
encapsulation of MPLS. You can now size each of the 5 STS pipes between
1 and a Xi STS1s (STS-1-Xv) as long as the sum of X1+X2+X3+X4+X5 <= 12.

Regards,

Maarten

Debanjan Saha wrote:
> 
> Fong,
> You're right. A channelize OC-12 can have 12 DS-3s (STS-1)within it.
> However, if all of them are terminating on
> the same LSR, I'm not sure why you'll use a channelized
> OC-12 and not an OC-12c.
> 
> Debanjan