[SR-Users] Kamailio s-cscf SRV <Root> query

Flavio Battimo flaviobattimo at gmail.com
Fri Dec 13 11:49:16 CET 2013


Hello,

working on Kamailio SCSCF module, when I receive an INVITE the serving
module should find the corresponding ICSCF to forward the INVITE. In
order to do this it should perform a NAPTR query, followed by a DNS
SRV query and a DNS A query.

In our case the serving has the following behavior:
1) it CORRECTLY make NAPTR query
2) it send an SRV query to resolve ICSCF service port having invalid
response 4 times.

After 4 times, so 20 seconds, it sends INVITE message to ICSCF at
default port 5060.
SRV query contains a null name, shown as <Root> in Wireshark. Current
DNS application (MyDNS) answer with a not implemented response.

I expect that the serving CSCF try to resolve the ICSCF making an SRV
query and an A query to discover the service port and ip address using
the domain returned by NAPTR query.

I have two questions:
It seems that SRV query is not valid, because it's not based on SIP
domain, do you think it's correct?

At least, is it possible to configure s-cscf to force an INVITE to be
sent always to the same interrogating?

-- 
Flavio Battimo
flavio.battimo at gmail.com
fbattimo at meetecho.com
skype: flaviobattimo



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