[Linphone-users] Getting Linphone to lookup SRV records in a DNS zone as well as a NAPTR record

[Swinney C.]

Hi All,

 

We have been trialling several SIP client and whilst LinPhone looks quite good, there seems to be a drawback in its implementation when trying to resolve SIP URI domain names to get the registered SIP service for that domain name.

 

We have only added SRV records to the DNS zone in order to point SIP URI lookups to our SIP service. We have register both UDP and TCP on 5060 to point to the public interface for our SIP entrance gatekeeper.

 

However, when you make a SIP call in LinPhone using a URI (e.g. address@hidden), LinPhone first gets the local DNS servers then tries to look up a NAPTR record. When this fails, LinPhone simply appends 5060 to the domain name lookup which resolve to  the standard A host record. Of course, the IP address resolved is actually pointing to the wrong server – in fact the web server.

 

Other SIP clients do not seem to have this issue and resolve the correct IP address from the SRV record as expected.

 

Example debug output from LinPhone:

---------------------------------------------------------------------

message: eXosip_dnsutils_naptr: DNS server (0): localdnssrv.com

message: eXosip_dnsutils_naptr_lookup: About to ask for domain.com NAPTR'

message: DNS resolution with domain.com:5060

message: getaddrinfo returned the following addresses:

message: x.x.x.x port 5060 --------------------------- (Resolved IP address of web server on A record)

message: Message sent: (to dest=x.x.x.x:5060)

-------------------------------------------------------------------------------

 

Is there any way to force LinPhone to lookup the SRV record instead of the NAPTR record, or should we have NAPTR records in our DNS zone as well? We also utilise H.323 and IAX.

 

Cheers,

 

Chris