SV: [Users] Route-header DNS lookup?

[Kerker Staffan]

hi
SRV records are all in place, but as I trace the DNS lookup queries sent
by the OpenSER host, it only asks for A records for "iptel1.ipatl.se" and
no NAPTR or SRV. the hostname that the NAPTR and SRV records points to is
"sip.iptel1.ipatl.se", but this is not resolved by OpenSER for the route-header
destination. 

but, for the initial INVITE, OpenSER correctly queries NAPTR and SRV rr to
resolv the hostname/IP of the server responsible for the domain "iptel1.ipatl.se". 

i'm familiar with the rfc3263, and all is set up correctly and working just fine. 

best regards,
/staffan 

>  -----Ursprungligt meddelande-----
>  Från: users-bounces at openser.org 
>  [mailto:users-bounces at openser.org] För Norman Brandinger
>  Skickat: den 6 juli 2006 14:57
>  Till: users at openser.org
>  Ämne: Re: [Users] Route-header DNS lookup?
>  
>  Hi Kerker,
>  
>  Perhaps there needs to be SRV records in the DNS server that 
>  manages iptel1.ipatl.se.
>  
>  Below are example SRV records.  If this is your first time 
>  working with SRV records, I strongly suggest reading some of 
>  the online doc that deals with them.
>  
>  _sip._tcp.iptel1.ipatl.se.             IN SRV 0 0 5060 
>  sip.iptel1.ipatl.se.
>  _sip._udp.iptel1.ipatl.se.             IN SRV 0 0 5060 
>  sip.iptel1.ipatl.se.
>  
>  Regards,
>  Norm
>  
>  Kerker Staffan wrote:
>  > hi
>  > i recently bounced into this problem, and i'm not sure here. 
>  > i'm running the openser-devel, with the cacheless 
>  db_mode=3. (works 
>  > fine btw)
>  >
>  > the record-route header received by the proxy on the other side 
>  > (SNOM4S), inserts the domain name (iptel1.ipatl.se) and not the 
>  > hostname (sip.iptel1.ipatl.se) in the record-route header, 
>  and uses the maddr=<ip_of_server> with the actual server IP address.
>  >
>  > now, when my client (behind the OpenSER) replies with an 
>  ACK to the 
>  > incomming OK, it uses the Route-header recieved in the 
>  RR-header, and 
>  > sends the ACK to OpenSER. i then get the following errors 
>  in OpenSER.
>  >
>  > ---
>  > /usr/local/sbin/openser[3583]: ERROR: mk_proxy: could not 
>  resolve hostname: "iptel1.ipatl.se"
>  > /usr/local/sbin/openser[3583]: ERROR: uri2proxy: bad host 
>  name in URI 
>  > 
>  <sip:4ffec4ce755c218a72228c6643cb3b6b at iptel1.ipatl.se:5060;ma
>  ddr=172.2
>  > 8.248.66;transport=udp;lr>
>  > ---
>  >
>  > the ACK i sent look like this:
>  >
>  > ---
>  > Request-Line: ACK sip:2307 at iptel1.ipatl.se;gruu=6fg9n6dl SIP/2.0
>  >       Via: SIP/2.0/UDP 
>  172.28.248.52:2051;branch=z9hG4bK-d96b1fvapkyn;rport
>  >       Route: <sip:172.28.248.10;lr=on;ftag=li9buf1i4p>
>  >       Route: 
>  <sip:4ffec4ce755c218a72228c6643cb3b6b at iptel1.ipatl.se:5060
>  ;maddr=		172.28.248.66;transport=udp;lr>
>  >       From: "Snom 2652" <sip:2652 at ipatl.se>;tag=li9buf1i4p
>  >       To: <sip:2307 at ipatl.se>;tag=hvseiz7kgb
>  >       Call-ID: 3c269d83900b-xj3ild14y880 at snom360
>  >       CSeq: 1 ACK
>  >       Max-Forwards: 70
>  >       Contact: <sip:2652 at 172.28.248.52:2051;line=cp4a7ljd>
>  >       Content-Length: 0
>  > ---
>  >
>  > as far as i understand, according the rfc 3263, the 
>  route-header may 
>  > contain domain name that has to be resolved using SRV.
>  >
>  > ---
>  > "6 Constructing SIP URIs
>  >
>  >    In many cases, an element needs to construct a SIP URI 
>  for inclusion
>  >    in a Contact header in a REGISTER, or in a Record-Route 
>  header in an
>  >    INVITE.  According to RFC 3261 [1], these URIs have to have the
>  >    property that they resolve to the specific element that inserted
>  >    them.  However, if they are constructed with just an IP 
>  address, for
>  >    example:
>  >
>  >    sip:1.2.3.4
>  >
>  >    then should the element fail, there is no way to route 
>  the request or
>  >    response through a backup.
>  >
>  >    SRV provides a way to fix this.  Instead of using an IP 
>  address, a
>  >    domain name that resolves to an SRV record can be used:
>  >
>  >    sip:server23.provider.com"
>  > ---
>  >
>  > now, OpenSER only asks DNS for an A record of the name 
>  recieved in the 
>  > route header, and since that's a domain name, it's 
>  unresolvable, and so the ACK is never sent.
>  >
>  > any hints or clues? 
>  >
>  > best regards,
>  > /Staffan Kerker
>  >
>  >
>  > --
>  > Staffan Kerker
>  > Saab Communications, Växjö
>  > p. +46 470 42185
>  > c. +46 705 391365
>  > m. staffan.kerker at saabgroup.com
>  >  
>  >
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