Subject: Re: Network Interworking Only in PWE3 (was: RE: Proposed changes to draft kamapabhava-01)

From: Eric Rosen <[email-masked]>
Date: Thu, 25 Apr 2002 12:50:52 -0400

> I can only say that one such draft (on ARP mediation) has been
> explicitly rejected at the PPVPN WG meeting in MPLS because
> the subject was declared "not in the charter". (Personally I think
> that this is a very useful document provoding a nice solution of
> a highly relevant problem, and I hope that the PPVPN WG will
> reconsider). 

Giles> I wasn't there, but from my  reading of the minutes Scott said it was
Giles> out of  scope of the current  charter and should be  discussed on the
Giles> list.  Is that  the same as "explicitly rejected"?   I suppose it may
Giles> be! 

I think Scott was simply mistaken to suggest that the ARP Mediation draft is
"out of scope".   It seems to me to  be as much in scope as  any other L2VPN
strategy.   Also, I don't  believe that  Scott's remark  was intended  to be
taken as any sort of final ruling.

---

From: "Vach Kompella" <[email-masked]>
Date: Thu, 25 Apr 2002 09:57:58 -0700

Since we are all opining on what Scott meant...

I think what he ought to have said is that IP related interworking is fine.  But
interworking of PWs at layer 2, for layer 2's sake, is out of scope.  The ARP
mediation draft is specifically IP related.

-Vach

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]On Behalf Of Eric
> Rosen
> Sent: Thursday, April 25, 2002 9:51 AM
> To: Giles Heron
> Cc: Sasha Vainshtein; [email-masked]
> Subject: Re: Network Interworking Only in PWE3 (was: RE: [PWE3] Proposed
> changes to draft kamapabhava-01)
>
>
>
> _______________________________________________
> pwe3 mailing list
> [email-masked]
> https://www1.ietf.org/mailman/listinfo/pwe3

---

From: "Bob Barrett" <[email-masked]>
Date: Sat, 27 Apr 2002 04:57:43 +0100

All

If I am following this track correctly, what I am reading is a requirement
to go from a circuit of one PHY type to a circuit of a different PHY type,
using pwe3 as a translation mechanism e.g. copper T1 > pwe3 > MPLS (over
whatever) > pwe3 > VC1.5 T1 over SONET.

So the arp functions required are to map the 'physical address' of the T1
port and the 'physical address' of the Sonet port to their respective IP
addresses. I put 'physical address' in quotes because there is no standard
definition of a T1 port address (as far as I know) in the same way as there
is a six byte MAC address for an Ethernet port, as used in the arp function
that those of us with grand children remember it. I guess that the IP
address will be owned by the pwe3 function with which the circuit port is
bound. I envisaged that the association of two pwe3 functions (and their IP
addresses) to form a circuit end to end would be an OAM&P function, even if
this function is automated behind a provisioning GUI of some sort.

So why do we need a new type of arp function? Don't tell me - I should read
the draft in full to find out ......

BTW - IP L2 looks to me like a technological oxymoron.

Thanks

Bob

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]On Behalf Of Vach
Kompella
Sent: 25 April 2002 17:58
To: [email-masked]; Giles Heron
Cc: Sasha Vainshtein; [email-masked]
Subject: RE: Network Interworking Only in PWE3 (was: RE: [PWE3] Proposed
changes to draft kamapabhava-01)

I think what he ought to have said is that IP related interworking is fine.
But
interworking of PWs at layer 2, for layer 2's sake, is out of scope.  The
ARP
mediation draft is specifically IP related.

-Vach

---

From: Giles Heron <[email-masked]>
Date: 27 Apr 2002 10:28:50 +0000

> whatever) > pwe3 > VC1.5 T1 over SONET.

well, that requirement (mediating between different L1 protocols) is
inherently solved by the L2 versions of PWE3 - as long as you are
running an L2 protocol for which you have a defined PWE3 encapsulation. 
I would imagine that for a copper T1 to a VC1.5 T1 some L1 flavour of
PWE3 would work fine whatever the L2 protocol?  (though I have to admit
that I'm not up with the L1 stuff...)

What we're talking about here is mediating between different L2
protocols (e.g. FR to Ethernet) when we have a defined L3 protocol (i.e.
IP).

> the draft in full to find out ......

the draft *mediates* between ARP functions.  It doesn't really define a
new one - and yes perhaps it is worth reading the draft before you join
the debate ;-)

> BTW - IP L2 looks to me like a technological oxymoron.

or a technological adjacency?  IP runs over L2 protocols after all, so
what is wrong with recognising this fact?

Giles

-- 
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Giles Heron    Principal Network Architect    PacketExchange Ltd.
ph: +44 7880 506185              "if you build it they will yawn"
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