Subject: Re: [Status] Summary of STATUS BOF and the next steps

From: [email-masked] (Noel Chiappa)
Date: Tue, 3 Sep 2013 12:54:18 -0400 (EDT)

> From: Hannes Gredler <[email-masked]>

    > what about this charter proposal ?

It looks like a good start to me, but one thing:

    > Stacked Tunnels for Explicit Routing (STER)

I actually like the name "segment routing". For one, it's a new term, so it
doesn't have any existing (overloaded) meaning.

For another, I find the 'ST' part of 'STER' a bit misleading because an ERD
might not be using a tunnel (as I normally think of it, which involves 'IPvN
in IPvN encapsulation' or 'L2 in IPvN encapsulation', or something like that)
to specify a path across itself; it might be using an MPLS path, for instance
(which I don't consider a tunnel).

'Segment routing' seems to me to capture the essence of what's going on; at
certain points along the overall path, an explicit route is picked for the
next segment of the overall path; hence, my liking for it.

I have no objection to using the term 'explicit routing' along with
'segment', so combinations like 'segment routing with explicit path
sections', etc, would all be fine with me too, although I don't have a
perfect suggested name to suggest.

	Noel

---

From: John E Drake <[email-masked]>
Date: Tue, 3 Sep 2013 18:10:43 +0000

Noel,

Comments inline.

Yours Irrespectively,

John

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf
> Of Noel Chiappa
> Sent: Tuesday, September 03, 2013 9:54 AM
> To: [email-masked]
> Cc: [email-masked]
> Subject: Re: [Status] Summary of STATUS BOF and the next steps
> 

[JD]  Inventing a new term to describe an existing phenomenon is not necessarily a good idea. 

> might not be using a tunnel (as I normally think of it, which involves 'IPvN in
> IPvN encapsulation' or 'L2 in IPvN encapsulation', or something like that) to
> specify a path across itself; it might be using an MPLS path, for instance

[JD]  From RFC3031:

 3.27. Tunnels and Hierarchy

   Sometimes a router Ru takes explicit action to cause a particular
   packet to be delivered to another router Rd, even though Ru and Rd
   are not consecutive routers on the Hop-by-hop path for that packet,
   and Rd is not the packet's ultimate destination.  For example, this
   may be done by encapsulating the packet inside a network layer packet
   whose destination address is the address of Rd itself.  This creates
   a "tunnel" from Ru to Rd.  We refer to any packet so handled as a
   "Tunneled Packet".

3.27.2. Explicitly Routed Tunnel

   If a Tunneled Packet travels from Ru to Rd over a path other than the
   Hop-by-hop path, we say that it is in an "Explicitly Routed Tunnel"
   whose "transmit endpoint" is Ru and whose "receive endpoint" is Rd.
   For example, we might send a packet through an Explicitly Routed
   Tunnel by encapsulating it in a packet which is source routed.

> certain points along the overall path, an explicit route is picked for the next
> segment of the overall path; hence, my liking for it.

[JD]  It must be a matter of taste as I find 'segment routing' to be startlingly non-evocative. 

> 
> I have no objection to using the term 'explicit routing' along with 'segment',
> so combinations like 'segment routing with explicit path sections', etc, would
> all be fine with me too, although I don't have a perfect suggested name to
> suggest.
> 
> 	Noel
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