[Sip] GRUU and grid

[Eric Rescorla <ekr at networkresonance.com>]

I recently made another pass through gruu-10 and I started wondering
about the use of the "grid" parameter. ISTM that it serves two
purposes:

1. To let a UA hang a context variable/indicator off of a URI.
2. To let a UA know it was referenced via a GRUU.

So, the grid is sort of doing double duty in two not terribly
related contexts. That's not always bad, but I fear it is
in this case.

First, wouldn't it be nice to be able to hang a context
variable/indicator off any URI, not just a GRUU?  I've seen this issue
come up in the context of e-mail spam, where users would like to be able
to mint new e-mail addresses (sort-of capabilities) for each use to
enable easy filtering.  It's obviously really nice to be able to do this
without the help of your service provider. If you could use grids
(probably renamed) with AORs or something like them, that would work for
this, right? 

Second, just from an evocative perspective, having a "grid" parameter
which can get into the To: one of two ways and which means 
"I was referenced via a GRUU" feels overloaded. Why not invent
a different parameter for "I was referenced via a GRUU".

-Ekr






_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sipping at ietf.org for new developments on the application of sip