Re: IP Layer 2 Transport over L2TPv3

Hi Prasad,

Please see inline.

Circa 9/20/2005 7:01 AM, Prasad Yadati said the following:
> Carlos,
> 
> Please see in-line.
> 
> Carlos Pignataro wrote:
> 
>> Prasad,
>>
>> Thanks. Please see a couple of comments inline.
>>
>> List,
>>
>> Any further comments on the request to accept this draft as a working
>> group document?
>>
>>
>> Circa 9/17/2005 5:50 AM, Prasad Yadati said the following:
>>
>>> Good one Carlos.
>>> How about just specifying it as "IP transport over L2TPv3".
>>>
>>
>>
>> Thanks.
>>
>> The "IP Layer 2" was added there for 2 reasons:
>> 1. To somehow differentiate raw-IP from framed-IP being transported over
>>    L2TPv3 while trying to reference the NSP function that interfaces the
>>    L2 AC with the IP PW Termination.
>> 2. Symmetry/parity name with the already defined PW Type for MPLS PWE3.
>>
> 
> But as per this draft, no "IP layer 2" information is transported.

Yes, only IP datagrams are transported, although there is a Layer 2
attachment circuit, and hence "IP Layer 2". The NSP function "extracts
IP datagrams from the Layer 2 frames" and that's the motivation for the
name, make a distinction from framed-IP. See below as well.

> Rather we are trying to prevent the same. For me, "IP layer 2" seems to
> be mis-leading.
> 
> 
>> "IP transport" may possibly be too generic for the procedures defined.
> 
> 
> Corlos, for me, "IP transport" seems more appropriate than current. In
> this case as far as L2TPv3 is concerned, it is transporting IP rather
> than layer 2 frame.

IMHO, "IP transport" is too generic, and does not fully convey what's
happening in the interface between the physical layer 2 interface and
the pseudowire termination. Other PW Types transport IP (framed-IP) as
well. I thought about "raw ip" and "native ip" but opted against them
for a similar reason. Any other suggestions?

> 
>>
>>
>>> Wondering whether we can have a generic "Layer 3 transport over L2TPv3"
>>> and specify transport of all layer 3 protocols (IP, IPX,....) in it
>>> including IP.
>>
>>
>>
>> Do you mean multiple L3 protocols at the same time over the session? I'd
>> think we can use existing L2 transports to accomplish that. OTOH, IP as
>> L3 stands out in the applications of an "IP L2" session.
> 
> Sorry I was not clear. I meant to combine specification of other layer 3
> data packets over L2TPv3 in one draft. May be that is not needed. We may
> have separate similar such of these drafts for other layer 3 protocols.
> Please ignore this comment.

OK. Thanks,

--Carlos.

> 
> Thanks
> Prasad
> 
>>
>> Thanks !
>>
>> --Carlos.
>>
>>
>>> Regards
>>> Prasad
>>>
>>> Carlos Pignataro wrote:
>>>
>>>
>>>> Hi All,
>>>>
>>>> We submitted the following `IP Layer 2 Transport over L2TPv3' draft:
>>>> http://www1.ietf.org/mail-archive/web/i-d-announce/current/msg06623.html
>>>>
>>>> that details the tunneling of IP datagrams directly over an L2TPv3
>>>> session, and defines the `CE IP Address AVP' as well.
>>>>
>>>> We would like it to become an l2tpext working group document, and seek
>>>> review, feedback and comments from the WG.
>>>> So we ask here for the draft to be accepted as work item for the group.
>>>> Your feedback will be most appreciated.
>>>>
>>>> Thanks,
>>>>
>>>
>>
> 

-- 
--Carlos.
Escalation RTP - cisco Systems