Subject: [rbridge] Initial cut at BoF request

From: Erik.Nordmark at sun.com (Erik Nordmark)
Date: Wed May 12 15:32:45 2004

We needed to request a BoF fairly quickly to make sure the IESG has time
to review it, so I've submitted a draft BoF request (see below).

I expect the details to change, especially the name :-)

Comments on the problem statement and suggestions for a better name
are especially welcome.

The authors of the rbridge internet-draft asked me if I would chair the
BoF which is fine with me. This does not mean I would necessarily be a
WG chair if a WG is formed as a result of the BoF.

   Erik

>----- Begin Included Message -----<

Date: Wed, 12 May 2004 15:26:19 -0700 (PDT)
From: "Erik Nordmark" <[email-masked]>
Subject: BOF request: ISITFUN
To: [email-masked], [email-masked], [email-masked]
Cc: [email-masked], [email-masked]

    a. Working Group or BOF full name with acronym in brackets:

IP Subnets In Topologies which are Flexible, Universal, and Nice [ISITFUN]

Note: we will almost certainly come up with a better name than this

    b. AREA under which Working Group or BOF appears:

Internet

    c. CONFLICTS you wish to avoid, please be as specific as possible:

VRRP, routing area meeting, SAAG, IPsec, IPv6, Multi6, v6ops

    d. Expected Attendance (figures from the previous IETF are sent when
       WG/BOF scheduling opens)
    e. Special requests (i.e. multicast):
    f. Number of slots:

one

    g. Length of slot:

two hours

       - 1 hour
       - 2 hours
       - 2 1/2 hours

Proposed BoF meeting chair: Erik Nordmark

Web page (which has a reference to the mailing list, archives, papers
and presentations with proposed solutions):

	http://www.postel.org/rbridge/

Problem statement:
   
It is desirable for an organization to have a fairly large campus
with a single IP address prefix, a rich physical topology,
where the network elements do not need to be configured,
where endnodes can move around without changing their IP addresses,
and where ARP and Neighbor Discovery traffic can be confined.

This functionality is often provided by bridges. 
However, bridges have disadvantages: routing
is confined to a spanning tree (precluding pair-wise shortest paths),
ARP and Neighbor Discovery packets must be carried across all the links,
the header on which the spanning tree forwards has no hop count,
spanning tree forwarding in the presence of temporary loops spawns
exponential copies of packets, nodes can have only a single point of
attachment, the spanning tree, in order to avoid temporary loops,
is slow to start forwarding on new ports, and it is not possible to take
advantage of the rich physical topology for capacity since the packet flows
are restricted to following the spanning tree.

Routers on the other hand avoid those disadvatages but have their own
disadvantages: IP addresses are link specific so a host that moves must
change its IP address, the routers must be configured with unique link prefixes
for each of the attached links, and the block of IP address space can not be
fully utilized because it must be partitioned across the different links.

The BoF will explore combining the benefits of bridges and routers without
requiring any changes on any of the hosts, IP routers, or bridges.
The design should support both IPv4 and IPv6.

>----- End Included Message -----<

---

From: touch at ISI.EDU (Joe Touch)
Date: Wed May 12 17:04:44 2004

>     b. AREA under which Working Group or BOF appears:

Seems like this isn't Internet unless it provides L3; since it provides 
L2, this might formerly be sub-IP, but currently might map better to 
Operations & Management.

> VRRP, routing area meeting, SAAG, IPsec, IPv6, Multi6, v6ops

L2VPN is the most specific I can imagine (it's not clear why that's in 
the Internet area either, IMO) that is active right now.

Zeroconf overlaps a little.

If there isn't a more specific place where NBMA subnets are covered, the 
general routing area might apply, though as you point out they might 
overlap with IPv6, Multi6 and v6ops (unlikely, but at least covers the 
bases). FWIW, the most relevant former group would (IMO) be ion in this 
regard, and certainly ion and its former precursor rolc are places to 
fish for participants ;-)

I don't see IPsec as relevant (it's ended anyway), or SAAG for that 
matter. There may be L2 security issues, or interesting uses of L3 
security inside the Rbridge, but unless we need modifications of those 
capabilities (not likely at the present at least), this is just a use of 
that technology.

> _______________________________________________
> rbridge mailing list
> [email-masked]
> http://www.postel.org/mailman/listinfo/rbridge
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From: touch at ISI.EDU (Joe Touch)
Date: Wed May 12 17:06:46 2004

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From: ftemplin at iprg.nokia.com (Fred Templin)
Date: Thu May 13 09:29:56 2004

Hello Erik,

As to names for the prospective WG, how about:

  Virtual Link eXtension (vlx)

or, if the above sounds too layer-2 centric:

  IP Virtual Link eXtension (ipvlx)

Fred
[email-masked]

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From: Radia.Perlman at Sun.COM (Radia Perlman)
Date: Thu May 13 11:52:47 2004

I like vlx. Though perhaps it's not clear what
a "virtual link" is. So perhaps "extended IP Subnet",
which might have a pronouncable acronym of EXIPS
(EXtended IP Subnets)

Radia

Fred Templin wrote:
>> This functionality is often provided by bridges. However, bridges have 
>> disadvantages: routing

---

From: ftemplin at iprg.nokia.com (Fred Templin)
Date: Thu May 13 12:10:51 2004

> which might have a pronouncable acronym of EXIPS

Would be better than "IP Subnet Extensions", which
would have an unfortunate acronym and pronounciation.

Fred
[email-masked]

>>> This functionality is often provided by bridges. However, bridges 
>>> have disadvantages: routing

---

From: ftemplin at iprg.nokia.com (Fred Templin)
Date: Thu May 13 12:48:48 2004

> IP Virtual Link eXtension (ipvlx)

Not intending to push my own proposal, but I just noticed that
strategic capitalization of this acronym would give: 'IPvLX'
which (treating the final two characters as roman numerals)
could allow for a claim that the new working group would
be an order-of-magnitude better than some others...

Fred
[email-masked]

---

From: Radia.Perlman at Sun.COM (Radia Perlman)
Date: Thu May 13 17:25:05 2004

Hmmm. If we went with IP Subnet EXtensions, we might
get larger attendance at the BOF.

Though I do like Fred's suggestion of IPvLX (IP Virtual Link eXtension), 

Radia

---

From: Cheng-Yin.Lee at alcatel.com (Cheng-Yin Lee)
Date: Thu May 13 20:32:56 2004

My interpretation of the draft is - a better bridge, with optimization
for IP traffic.
It is perhaps captured better by Margaret Wasserman's suggestion,
HyBridge or a hybrid bridge/router (incidentally the name of this
mailing list too). 
If the work is going to be on bridging IP traffic or IP subnet only,
then IP Subnet EXtensions sounds fine. Would the group then consider IP
Subnet EXtensions for different types of access networks (I know this is
not easy) ?
I have to admit Fred Templin's suggestion is tempting ;-)

Regards
Cheng-Yin