Subject: RE: ATM-LSR

From: "Albert Pang" <[email-masked]>
Date: Sat, 20 Nov 1999 15:29:41 -0000

Peter Ashwood-smith wrote: 
>   The ATM-LSRs must be running IP/TCP/UDP or you cannot run MPLS on them.
> Normally one of the VCCs on a port is configured to run classical IP on 
> ATM. It is over this VCC that all normal IP traffic flows and it is over
> this VCC that OSPF/RIP etc. will operate to establish connectivity. TCP
> then operates over this VCC also and is used by MPLS for label requests
> and mappings.
	[Pang, Albert [HAHN:2870:EXCH]]  
	Now the hard question is, is there any recommendation on what ATM
Service Category 
	one should use for this VCC.  'cbr', 'nrt-vbr', 'rt-vbr', 'ubr',
'abr'?

	In 'draft-ietf-mpls-atm-02' (seciont 7.1) it is mentioned that:

	   "The default VPI/VCI value for the non-MPLS connection is VPI 0,
VCI
	   32.  Other values can be configured, as long as both parties are
	   aware of the configured value."

	But there is no recommendation on what ATM service category it
should.

	The use of this IP/1483/ATM connection seems to have conflicting
requirements:
	1) LDP and other routing protocols runs on top of it.  The priority
should be high.
	2) Normal IP traffic (destinations that do not have a FEC) also goes
through 
	   this VCC (not as important as LDP/OSPF).

	How should we resolve this?  Is there a way to setup yet another
separate
	channel (vpi.vci) for signaling (e.g. LDP/OSPF) and not for normal
traffic.

	Thanks.

	Albert Pang
	Nortel Networks Germany

---

From: GeeVarghese John <[email-masked]>
Date: Mon, 22 Nov 1999 12:47:15 -0500

Hi Peter Ashwood-smith,

Please answer my questions

Couple of weeks back I read from the mailing list that
MPLS  means - Multi Protocol Label Switching ..
In that case why this coupling with IP

>> The ATM-LSRs must be running IP/TCP/UDP or you cannot run MPLS on
them.

Is it because the technology is currently addressing only IP ..

One more question  Please anyone can answer ..

when people  talk Voice over MPLS what does it mean ..
what is the transport mechanism ..
Is it IP only ? or what is the role of IP there ??

Thanks in advance

GVJ

Albert Pang wrote:

>         "The default VPI/VCI value for the non-MPLS connection is VPI
>      0, VCI
>      1) LDP and other routing protocols runs on top of it.  The
>      priority should be high.
>      2) Normal IP traffic (destinations that do not have a FEC) also
>      goes through
>      channel (vpi.vci) for signaling (e.g. LDP/OSPF) and not for
>      normal traffic.
>
>      Thanks.
>
>      Albert Pang
>      Nortel Networks Germany
>
>
>
>
>

---

From: Antti Kankkunen <[email-masked]>
Date: Mon, 22 Nov 1999 18:10:57 -0500

> Is it IP only ? or what is the role of IP there ??

Voice over MPLS can mean both "Voice over MPLS" and "Voice over IP over
MPLS". Both have some specific applications and both require some new
effort on the standardization front.

In case of "Voice over MPLS" the voice packets are not encapsulated in
IP headers. However, the LSP setup is still based on RSVP/CR-LDP, which
implies at least IP addressing and possibly even the use of IP routing.
The end points of the voice connection are addressed using IP addresses
and the LSP may be setup using IP routing.

Please join our mailing list for more details. We are commencing the
discussion on December 1st.
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Thanks and best regards,

Antti K.
--
Antti Kankkunen
Integral Access Inc.
321 Billerica Rd.
Chelmsford, MA 01824
Phone: +1 978 256 8833 x 232
Mobile: +1 617 513 2172
Fax: +1 978 256 8077
e-mail: [email-masked]