SRV Records for Registration

[Patrick Sparkman]

Can someone tell me or direct me to a document that covers what SRV records are used for registration of SIP devices?  I know h323rs is used for H323 registrations, but don't know what is used for SIP.  Is it possible to seperate the calling SRV records from the registration ones, if so, which records would those fall under?

Thanks

Patrick

[Chris Swinney]

For the devices we use (Jabber, MXP C Series, 7960G Phones etc), we normally specify the actual device (or cluster) FQDN or IP address to point the device to register directly, so SRV are not an issue

So, our devices point directly to "vcs-e.mydomain.com" to register (and in the case of Jabber, provision then register, for instance).

But our SRVs are something like:

_sip._udp.mydomain.com  IN    SRV    0 0 5060  vcs-e.mydomain.com.

_sip._tcp.mydomain.com   IN    SRV    0 0 5060  vcs-e.mydomain.com.

_sips._tcp.mydomain.com IN    SRV    0 0 5061  vcs-e.mydomain.com.

So calls to sip:me@mydomain.com lookup the SRV, which again - in this case - points to "vcs-e.mydomain.com".

I don't think I have even tried to register a device to a DNS name such as a top level domain "mydomain.com", but if this works then I suspect it would use the same SRVs

Chris

[Wayne DeNardi]

Hi Patrick,

IETF RFC 3263 defines how SIP agents can leverage DNS to resolve a SIP Uniform Resource Identifier (URI) into the IP address, port, and transport protocol of the next hop contact. The method in RFC 3263 may be applied to SIP register messages.

There is no specific "ls" /  "rs"  "cs" or "be" SRV records with SIP as there is for H.323, only the _sip._udp, _sip._tcp, and _sips._tcp mentioned above.

Cheers

Wayne

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