CUBE does not send OPTIONS signal

[samhopealpha]

Hi Everybody, 

Currently i am using the ISR4431 as a cube, add an additional pstn sip to telco, but failed to make outbound call
Other SIP connection to pstn are fine, except this newly add sip connection.

• Connection path 
  CUCM ---(sip)--- CUBE ---(sip)--- Telco PSTN

When making an outbound call, CUBE receives the INVITE from CUCM, but it does not sent INVITE to PSTN telco.

Verified
- Cube is able to ping pstn sip server both ip and fqdn (10.132.1.1 and ippbx.abc.net)

Some abnormal symptoms are found
- the CUBE does not send the OPTION to telco.
- show dial-peer voice summary, the dial-peer state is 'busy out'

Here is the part of the config

!
ip host ippbx.abc.net 10.132.1.1

!
dial-peer voice 91 voip
description *** OUTBOUND - CUBE to PSTN  ***
destination-pattern 4442T
session protocol sipv2
session target dns:ippbx.abc.net
session transport udp
voice-class codec 400
voice-class sip options-ping 60
voice-class sip options-keepalive
voice-class sip bind control source-interface GigabitEthernet0/0/2
voice-class sip bind media source-interface GigabitEthernet0/0/2
dtmf-relay rtp-nte
no vad

!

Is anybody know what's the problem?
Thanks in advance

Sam

[Jonathan Schulenberg]

You need to suffix the destination UDP port to your session target command.

session target dns:server.domain.tld:5060

The default behavior of the dns: prefix is to query for SRV records - which you didn’t add under ip host, only an A record. It isn’t  sending OPTIONS ping because it can’t resolve that destination. Specifying the port forces IOS XE to skip the SRV lookup and query for the A record.

[samhopealpha]

Thanks for the information. 

I have tried the following ways, but all are failed...

1st try: 
session target dns:ippbx.abc.net:5060

2nd try:
Add the A and SRV records in DNS server 10.10.10.170 
A record: ippbx.abc.net 10.132.1.1
SRV record:
_sip._udp.abc.net 10 10 5060 ippbx.abc.net
_sip._tcp.abc.net 10 10 5060 ippbx.abc.net

Cube 
no ip host ippbx.abc.net 10.132.1.1
ip name-server 10.10.10.170

Cube can ping the ippbox.abc.net
then tried to update the dial-peer  with and without :5060
session target dns:ippbx.abc.net 
session target dns:ippbx.abc.net:5060

3rd try:

change the session target to ipv4
session target ipv4:10.132.1.1

It seems like even it's using IP, it is still not sending the OPTION out ...

[samhopealpha]

I have tried to re-simulate the same case in my lab, and found that PSTN VG does receive the SIP options signal from CUBE. 

However, the CUBE (debug ccsip message) could show any SIP message, "EXCEPT outbound OPTION signal" <<<<<
I think this is a bug

Thank you @Jonathan Schulenberg , your information also value-added my knowledge ~

[Roger Kallberg · Accepted solution]

Do a debug of non call events to see the option ping.

[samhopealpha]

@Roger Kallberg thanks for the answer, that works perfectly.

but why the CUBE can see the incoming OPTIONS signal, but not the outgoing OPTIONS signal when "non-call debug is OFF"
i suppose both incoming and outgoing OPTIONS signals should belong to the same thing

[Roger Kallberg]

I don’t know. You’d have to ask the developers of this to really know.

[Jonathan Schulenberg]

My assumption is that the debug process doesn't understand in-dialog vs. out-of-dialog state on the receiving side. It's probably much easier to reliably distinguish between the two on the sending side. None of us need the debug command guessing wrong and hiding/omitting messages it shouldn't.

PS- If you haven't already stumbled onto VoIP Trace it's a remarkably efficient way to pull debugs for an actual call (not options ping). Worth getting proficient with IMO.