[afnog] DNS SRV Records

[Andy Davidson]

On 17 Oct 2007, at 16:54, Bruce Zamaere wrote:

> -------- cut here --------
> _sip._udp  IN      SRV 0 1 5060 voip.example.com
> voip.example.com.         IN A             10.9.1.1
>  ----------cut here ---------------
> I expected this to work but when I try to query my server using the
> host command I get:
>
> #host -t SRV example.com
> example.com has no SRV record

Your sip client isn't going to query for an srv record called  
example.com, and actually one does not exist.  If your sip clients  
support srv, they will know to query for _sip._udp.example.com

andy at pringle:~ $ host -t SRV localphone.com
localphone.com has no SRV record
andy at pringle:~ $ host -t SRV _sip._udp.localphone.com
_sip._udp.localphone.com has SRV record 1 0 5060 proxy.localphone.com.


I just fired up sjphone and dialed a-valid-sip-alias at localphone.com,  
and the invite was correctly formed when it reaches the proxy - in  
other words the srv record was honoured.


If you are debugging because something is not working, let me know  
what I should be able to call, and I will try it.  (In my experience,  
the number #1 reason for people thinking their srv records are not  
working is that they've forgotten to set srvlookup=yes in Asterisk's  
sip.conf, but you may not be using that technology, or you may not  
have tried debugging yet.)

Best wishes,
Andy