Noble Antony T wrote:
>
> Hi,
>
> I need some clarifications about the conversion of IM URI to SIP URI.
> Thanks in advance...
>
> According to RCF3861
>
> 3. Address Resolution <
http://rfc.net/rfc3861.html#s3.>
>
> /The symbolic name used in the Service field of the SRV record is
> "_im" for instant messaging... However, the advertisement of these
> services in the DNS is incomplete if it does not include the protocol
> that will be used to instantiate the instant messaging or presence
> operations...
>
> ... the Protocol field of the SRV record contains an
> IANA-registered label corresponding to the underlying instant
> messaging or presence protocol being advertised.
> /
>
> I need to send a MESSAGE with a request URI
>
im:fred at example.com <mailto:im:fred at example.com>
> and it is to be resolved into corresponding SIP URI.
>
> what should I query to get the corresponding SIP URI..?
I agree that this is a bit confusing. Unlike resolution of (say) an
http: or mailto: URI, there are several steps involved in resolution of
an im: URI.
If you have im:fred at example.com then you need to resolve that to an
address for a registered IM protocol:
http://www.iana.org/assignments/im-srv-labels
Surprisingly, there is only one registered IM protocol: XMPP. Did
someone forget to register SIP/SIMPLE?
Assuming that SIP/SIMPLE will be registered (and assuming that the
registered <Proto> label will be "_sip") then you would attempt to
resolve the target domain per Section 3 of RFC 3861. So you would
attempt to resolve the following:
_im._sip.example.com.
That would result in a resolution to a domain that handles SIMPLE IM
traffic for example.com, such as perhaps
simple.example.com.
Thus im:fred at example.com would resolve to sip:fred at simple.example.com.
Or at least that is my understanding. Perhaps Jon Peterson is a better
person to ask, since he authored RFCs 3859, 3860, and 3861.
Peter
--
Peter Saint-Andre
https://stpeter.im/