Cisco 2921 SW15.5.3M6 issue with SIP-Trunk to Faxserver

[at]

Hi,

we use since 6 Years a Faxserver (Rightfax 9.4 FP1SP4 with Brooktrout SR140 SIP Call Control Module) 

Incoming Faxes we send from Cisco Router 2921 via SIP-Trunk directly to the Faxserver.

Site 1 : PSTN --- C2921_Site1 ---- SIP ---- Faxserver

Siter 2 : PSTN ---- C2921_Site2 ------ SIP ------ Faxserver (same Server as for Site1)

Siter3 ....

We also have a central CUCM-Cluster (11.5) which als works with the Routers on the Sites (H323)

On the Cisco Router 2921 we use 15.4.3M4

Last December we updated one Site-Router to 15.5.3M6a 

After the upgrade the incoming Faxes stopped to work, communication with CUCM Cluster works normally ...

After downgrading the Site Router  to 15.4.3M4 the Incoming Faxes worked normal again.

We did an upgrade to Cisco IOS 15.6.2T2 and we saw that the Incoming Faxes worked.

We test with 2 Site Routers - Both Routers had Problems with 15.5.x and Fax 

Seems there is a problem with Cisco 15.5.3M6a ???

.

1.IOS 15.5.3M6a: On the Faxserver we receive SIP Inivte but Faxserver does not answer

  ...

                Cisco Router                                                                                   Faxserver

2. IOS SW 15.6.2T3 : We see the sip-invite and the answer from Faxserver ...

                               Cisco Router                                                                              Faxserver

The only thing we see -

15.5.x send sip-invite with Port 49xxx 

15.6.x send sip-invite with Port 61xxx 

Does anybody have any idea about our "issue" ?

regards

Alex

[Mohammed al Baqari]

Can you share full debug. Also, look in the fax server logs to look for any
errors. I suspect that new SDP attributes or SIP headers added to later IOS
while your fax server don't like them

[at · Accepted solution]

Hi,

we fixed the Problem

the router sent an sip invite with Date: ... MET ... 

...

Sent:

INVITE sip:+xxxx@xxxx:5060 SIP/2.0

Via: SIP/2.0/UDP xxxx:5060;branch=z9hG4bK122053

Remote-Party-ID: <sip:xxxxx@xxxxx>;party=calling;screen=yes;privacy=off

From: <sip:xxxxxxx@xxxxx>;tag=5C309158-2159

To: <sip:xxxxxxx@xxxxxxx>

Date: Thu, 08 Feb 2018 13:05:18 MET

Call-ID: 29D74BC3-BFF11E8-A1CAB27E-79793574@xxxxxxx

...

there is a known cisco bug in 15.5.3M6  

we created a sip Profile wich modifes the Timezone (MET will be replaced/changed to GMT)

and after that Change the Fax works as expected .

!

voice class sip-profiles 111

 respnse ANY sip-Header Date modify "MET" "GMT"

 request ANY sip-Header Date modiry "MET" "GMT"

!

voice Service voip

 sip

   sip-profiles 111

!

!

regards

Alex

here the Cisco Bug

CSCvf07153

SIP Date header format not in GMT Format

CSCvf07153

Description

Symptom:
CME and CUBE populate the SIP Date Header the timezone configured on the router and not as GMT like previous versions of IOS and IOS-XE Code.

This is against RFC 3261 as per Section 20.17 Date.

This is causing issues with 9971 phones as they are coded in such a way that they only understand GMT.
This can also cause interop issues with ITSPs and other devices who are coded to only understand GMT Date headers.

Conditions:
15.6(3)M2
15.5(3)M6

Workaround:
Workaround 1: Set the router's clock as GMT.
 
!
no clock timezone EDT
clock timezone GMT
!

Workaround 2: You  can modify the SIP message that the router sends to the network.

!
voice class sip-profiles 111
response ANY sip-header Date modify "EDT" "GMT"
! 
voice service voip
sip
  sip-profiles 111
!

Note: You can replace the EDT in the sip-profile with the timezone configured on router.
The timezone can be checked by issuing"show clock "

[Kayman42]

Thank you so much!  I was having this same issue with one of our phone systems.