[Asterisk-Users] Problem with multiple phones behind firewall

[Harold Workman]

Hi,

I am having a problem when I add multiple phones behind a Symmetric
Firewall.  Heres my situation.


11am - Phone A registers with *
11:01am - test call to Phone A.  Call works fine.
11:02am - Phone B registers with *
11:03am - test call to Phone A fails, test call to phone B works fine.
11:04am - test call from Phone A to Phone B and vice versa works fine.
11:05am - Phone A re-registers with *.  Test call to Phone A works fine now.



This happens on almost all occasions.  When I see one phone register behind
a firewall, i then see the "Retransmitting #5 (NAT):" messages, until I
received the
"Jul 13 15:11:09 WARNING[1133718080]: chan_sip.c:673 retrans_pkt: Maximum
retries exceeded on call 0576f80274aebde8796e5d4b2444c2a9 at 64.72.107.10 for
seqno 102 (Non-critical Request)"


I have nat=yes in my sip.conf file.  I have tried using the qualify command,
but I have never been able to get it to work behind a symmetric firewall to
both a unknown sip phone and xlite.
The moment I turn on qualify, I see the Options request sent out, and on the
client see the options request, but I never see a response on * from the
clients.



Here is what my sip.conf looks like...


[general]
port = 5060
bindaddr = 64.72.107.10
context = exten
maxexpirey=3000
defaultexpirey=300
disallow=all
allow=alaw
allow=ulaw

[123456]
type=friend
secret=k3v1n
nat=yes
canreinvite=no
host=dynamic
dtmfmode=rfc2833
context=cytelmain

[789012]
type=friend
secret=cytel
nat=yes
canreinvite=no
host=dynamic
dtmfmode=rfc2833
context=cytelmain



What else is there for me to try to resolve my NAT problem with multiple
users behind a symmetric firewall?


Thanks,



Harold