[prev in list] [next in list] [prev in thread] [next in thread] 

List:       sip-implementors
Subject:    Re: [Sip-implementors] Chaos in Dialog subscription "standar"
From:       "Dale Worley" <dworley () nortel ! com>
Date:       2008-12-31 23:18:51
Message-ID: 1230765531.2950.9.camel () victoria-pingtel-com ! us ! nortel ! com
[Download RAW message or body]

On Wed, 2008-12-31 at 00:34 +0100, Iñaki Baz Castillo wrote:
> But what I see is the fact that each vendor implements "dialog" subscription 
> in a propietary way. For example, when configuring a Li**** phone for dialog 
> subscription it requires to choose between subscription server type 
> (Ast*****, Broa******, RFC4235, ...).
> 
> This is just annoying for me. There are more and more new RFC's and drafts 
> based on RFC 4235 for different purposses, when the fact is that most vendors 
> implement such things as they want (it means: in a propietary way).
> 
> This is no good for interoperability. Any explanation of this sad reality? 

Could you explain exactly what you mean by "proprietary" here?

It is true that RFC 4235 leaves the UA a great deal of latitude which
data items to include in the event, but in principle the consumer of the
event should be able to function correctly if the UA provides the
minimum subset that the consumer needs.

It would probably be useful if you published a summary of the problems
you have discovered.

As for *why* this is so, I think it's due to the general tendency of
phone vendors (and other vendors) to expend as little effort as possible
on implementation.  This leads to responses from vendors like the one we
received from Pol****, "It works with Broadwords."  I suspect that in
the telecom world this is even worse than other parts of the computer
world, because vendors are used to having to tweak their systems to work
with each particular other vendor; there is little understanding of the
concept of "standards conformance" in practice.

Dale




[prev in list] [next in list] [prev in thread] [next in thread]