Subject: AAL2 Frames, Fischer and Brayley

From: "Daniel Feldman" <[email-masked]>
Date: Thu, 23 May 2002 10:31:31 +0200

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.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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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From: [email-masked]
Date: Thu, 23 May 2002 10:39:00 -0500

Daniel,
    What is the servie that is to be provided?
 
 If all the AAL2 connections that are on one VC are to be transported 
over an MPLS LSP and then mapped back to a single VC then an AAL2 
mapping like the AAL5 mapping is probably not a good idea. AAL2 frames 
are typically smaller than AAL5 frames and can be subcell in size.  
Having MPLS overhead per AAL2 frame would be very inefficient. A 
multicell encapsulation approach (if the delay is tolerable) would be 
much more efficient.
 
On the other hand if the service is to actually switch the individual 
AAL2 connections from one VC to a multiple of other VCs then you are 
talking about AAL2 switching. In which case I think it would still be 
advantagous to transport multiple AAL2 frames in one MPLS frame due to 
the overhead.
i.e. a node could have an AAL2 switching function which would switch the 
AAl2 connections between VCs and then transport the VCs. Or an 
alternative is to map multiple AAL2 frames into an LSP without any ATM 
overhead.
 
Robert Dianda

-----Original Message-----
From: daniel [mailto:[email-masked]]
Sent: Thursday, May 23, 2002 3:32 AM
To: pwe3
Cc: matthew.bocci; john.fischer; jbrayley
Subject: [PWE3] AAL2 Frames, Fischer and Brayley

        Hello PWE3ers,

        Regards,

        Daniel Feldman.

Daniel Feldman

mobile: +972(55)99-0299

fax:      +972(4)959-4944

---

From: "Andrew G. Malis" <[email-masked]>
Date: Thu, 23 May 2002 14:33:00 -0400

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).
>
>         How about adding this option to the Brayley and Fischer proposals?
>

---

From: "Daniel Feldman" <[email-masked]>
Date: Fri, 24 May 2002 11:07:58 +0200

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.zi
p

    Regards,
        Daniel.
-----Original Message-----
From: Andrew G. Malis [mailto:[email-masked]]
Sent: Thursday, May 23, 2002 8:33 PM
To: Daniel Feldman
Cc: [email-masked]; [email-masked];
[email-masked]; [email-masked]
Subject: Re: [PWE3] AAL2 Frames, Fischer and Brayley

Daniel,

Regards,
Andy

------

        Hello PWE3ers,

        Regards,

        Daniel Feldman.

Daniel Feldman

mobile: +972(55)99-0299

fax:      +972(4)959-4944