Hello,

I am having some performance issues with Openser and I tend to believe they are related with DNS. So I am trying to figure out when and why Openser is doing DNS queries. Doing ngrep on port 53 I realized that right before sending out the "100 trying -- your call is important to us" message, Openser is doing a reverse DNS lookup for the IP where the INVITE came from. So the sequence is something like:

client Openser DNS

|---INVITE------------------------>|

|<---407 Proxy Auth Reqd---|

|---ACK--------------------------->|

|---INVITE------------------------>|

|---client IP?-------->|

|<-------------------------|

|<--------------------100 trying---|

I am using Openser-1.1.0-notls and in my script I have

dns=no

rev_dns=no

So first question is whether this DNS query is necessary and how I could avoid it.

What is furthermore confusing is that I have a test system with the same Openser version and same script, where this DNS query is not happening. Looking into the production system I found the following:

ser2:/usr/local/openser-1.1.0-notls/sbin# ldd openser
        linux-gate.so.1 => (0xffffe000)
        libdl.so.2 => /lib/tls/libdl.so.2 (0x55571000)
        libresolv.so.2 => /lib/tls/libresolv.so.2 (0x55574000)
        libc.so.6 => /lib/tls/libc.so.6 (0x55587000)
        /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x55555000)

whereas the test system shows:

sertest:/usr/local/openser-1.1.0-notls/sbin# ldd openser
        libdl.so.2 => /lib/libdl.so.2 (0x7002c000)
        libresolv.so.2 => /lib/libresolv.so.2 (0x70040000)
        libc.so.6 => /lib/libc.so.6 (0x70064000)
        /lib/ld-linux.so.2 (0x70000000)

So the two systems link to different libresolv.so libraries. Is the tls/libresolve.so that is responsible for the DNS query? Given that in both cases I am using the notls version of Openser 1.1, why is there a difference between the two?

thank you for any help

George

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