Hi Andrew,
as far as I know, the TDMoIP approach is very nice, but it is:
a) Not sure to be approved as the TDMoPSN chosen draft, since many people back CESoPSN.
b) Not the place where ATMoIP should be treated.
The technique described in TDMoIP is bandwidth effective: multiplex some AAL2 CPS packets over one Ethernet/MPLS/UDPoIP flow, and send them. However, it does not address the AAL2 switching problem described by Robert Dianda in his previous mail.
In fact, in UTRAN, there is a one-to-one equivalency between (AAL2 CID + ATM VCI + ATM VPI) and (UDP Source Port + UDP Destination Port + IP Source Address + IP Destination Address).
This means that the mapping should take care of the CID, i.e., only CPS packet with the same CID are sent over the same PSW. I know this may multiply the number of Pseudo Wires by a factor of 256, but that's exactly the kind of problems people making Network equipment for UTRAN deal with, be it AAL2/ATM or UDP/IP based UTRAN.
How about using the algorithm I proposed in January to 3GPP:
ftp://ftp.3gpp.org/tsg_ran/WG3_Iu/TSGR3_26/Docs/R3-020035_AAL2_to_UDP.zip
Regards,
Daniel.
-----Original Message-----
From: Andrew G. Malis [mailto:Andy.Malis@vivacenetworks.com]
Sent: Thursday, May 23, 2002 8:33 PM
To: Daniel Feldman
Cc: pwe3@ietf.org; matthew.bocci@alcatel.co.uk; john.fischer@alcatel.com; jbrayley@laurelnetworks.com
Subject: Re: [PWE3] AAL2 Frames, Fischer and Brayley
Daniel,
Check out http://www.ietf.org/internet-drafts/draft-anavi-tdmoip-03.txt, which discusses how to encapsulate AAL1 and AAL2 over MPLS.
Regards,
Andy
------
At 5/23/2002 10:31 AM +0200, Daniel Feldman wrote:
Hello PWE3ers,
I am also part of the RAN3 group of 3GPP, which deals with IP and ATM transport in UMTS Radio Access Networks (UTRAN).
UTRANs are probably the most common user of AAL2 and, as you know, AAL2 has an SSCS layer very similar to AAL5.
How about adding this option to the Brayley and Fischer proposals?
The extra fields needed concern the AAL2 user (up to 26 users).
Regards,
Daniel Feldman.
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Daniel Feldman
System Architecture Team Leader, IC4IC Ltd.
office: +972(4)959-4644 ext. 121
mobile: +972(55)99-0299
fax: +972(4)959-4944
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