Help with response to "OPTIONS" request issues


we have ATT VoIP service and at one location i have a perplexing issue.

the service will stop responding to “OPTIONS” 12.194 is ATT and 10.20 is the asterisk running 11.25.3

(Please see below) normally i see line 1 as ATT sending “OPTIONS” and in line 2 the Asterisk responds 200 OK

then in line 3 when asterisk requests “OPTIONS” the asterisk in line 4 reply’s with |ICMP|505|Destination unreachable.

Please any help to understand this and how to resolve.


|1 12.194.XXX.XXX|10.20.XXX.XXX|SIP|472|Request: OPTIONS sip:10.20.XXX.XXX:5060 | |
|2 10.20.XXX.XXX|12.194.XXX.XXX|SIP|603|Status: 200 OK | |
|3 12.194.XXX.XXX|10.20.XXX.XXX|SIP|477|Request: OPTIONS sip:10.20.XXX.XXX:5060 | |
|4 10.20.XXX.XXX|12.194.XXX.XXX|ICMP|505|Destination unreachable (Port unreachable)|

That is not stopping responding to OPTIONS, it is stopping accepting any SIP request at all!

Thank you for the reply.

this is very odd as it only happens on the ATT sip connections, i have a sip phones and iax2 connections and it does not happen there. And it happens so far predictability between 8:00 and 8:30 am and ends at between 10:00 am and noon.

this is running on a HP dl 360 g5 server, i changed from the on board nic to a Intel nic and it made no difference.

Any ideas or troubleshooting tips?

Thank you


Contact ATT.

Use TCPDump to find the source IP address of the ICMP (to see if it is being generated by an intermediate firewall, or the machine hosting their SIP server).

thank you for responding.

there is no intermediate firewall, the connection is from the asterisk pbx to a HO 2930 switch then to the ATT cisco router.

I have replaced the HP switch, the cables.

unfortunately it is beyond my skills to answer your question without a little coaching on how to provide the information.

based upon talking to ATT and what i see it looks like asterisk is trying to verify the connection however ATT does not reply .

as i am not familiar with how thing work digging this deep i do need some coaching and help.

Thank you for understanding.


There isn’t really a connection, because it is UDP. However, using connection loosely, the failure is showing that the verification is failing because the connection really is broken. You would get the same ICMP unreachable if you sent an INVITE, rather than an OPTIONS.

Thanks again for answering

it is ATT that claims that i do not respond to their “OPTIONS” request, however as virtually traffic was moved off this server i could watch the sip debug in real time and i did not see anything come in when the asterisk did not respond.

with he port mirrored i did see att come in on wire-shark.

i replaced the switch and Ethernet cables as there where some layer 1 errors on the port connecting to ATT.

I will watch to see if that helped.

thank you