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New Member

SIP Calls dropping after 32sec

Hi Cisco Supportforum,

I 'm having problems with my Cisco IP Phone 525g2, if I make an outgoing call it drops exactly after 32sec. On incoming calls there are two behaviors, everything is fine and the call in stable or the telephone rings but picking up the headset doesn't initiate an SIP session and the phone keeps ringing.

I am running the IP Phone behind a Zone Based Firewall on an ISRg2 1941 Router, the Firewall config looks like this:

class-map type inspect sip match-any SIP-VIOLATION
 match  protocol-violation
!
class-map type inspect match-any SIP-TRAFFIC
 match protocol sip
!
class-map type inspect  match-any STUN-TRAFFIC 
 match protocol stun
!
class-map type inspect match-any MSRPC-TRAFFIC
  match protocol msrpc
!
!
policy-map type inspect sip SIP-VIOLATION-PASS
 class type inspect sip SIP-VIOLATION
  allow
  log
!
policy-map type inspect LAN-TO-WAN
 class type inspect SIP-TRAFFIC
  inspect
  service-policy sip SIP-VIOLATION-PASS
 class type inspect STUN-TRAFFIC
  inspect
 class MSRPC-TRAFFIC
  Inspect
!
policy-map type inspect WAN-TO-LAN
 class type inspect SIP-TRAFFIC
  inspect
  service-policy sip SIP-VIOLATION-PASS
 class type inspect STUN-TRAFFIC
  inspect
 class MSRPC-TRAFFIC
  Inspect

The IP Phone is connect to a C3560CG switch, the switch is connected to the 1941 Router (Layer 3). My SIP provider is SIPgate.

Attached you find two packed captures monitored in the uplink-port from the 3560CG switch.


Best regards
Nils Storm

Everyone's tags (1)
15 REPLIES

Hello Nils,From both the

Hello Nils,

From both the packet capture i can analyze that SIPgate( 217.10.79.9) is only able to receive INVITE message from 192.168.21.10.

For Inbound call SIP gateway is keep on sending INVITE message as it never received 100/Trying , 180/Ringing  and 200/OK. That's why caller only hear ringing tone( due to early media from Telco) and call did not setup .

For outbound call SIP gateway received INVITE and process the call setup with 200/OK then RTP established but SIP GW didn't received ACK for 200/OK and again it keep on sending 200/OK  message till its times out i.e. 30 second and then call disconnected from SIP gw side.

 

This is something related to firewall which i don't have experience on , wait for some more time i am sure someone from CSC will help you on this.

 

Thanks

Manish

New Member

Hi, here are some more packet

Hi,

 

here are some more packet-captures, from the router. The router runs the Zone based Firewall.

 

Best regards
Nils Storm

Can you let us know with a

Can you let us know with a simple call flow diagram that where these IP belongs to ....

 

217.10.68.147
192.168.21.10
172.20.40.4
217.10.78.9
217.10.79.9
46.59.194.32

New Member

Hi,              ZB Firewall

Hi,

 

             ZB Firewall           Layer 3                                           VLANs

<------> 1941-Router <-----------------------> 3560-Switch <-----------------------> 525v2-IP Phone

Outside Int      Inside Int                Uplink Int               Voice VLAN         Phone IP

46.59.194.32  192.168.250.1/31   192.168.250.0/31  192.168.21.1/24  192.168.21.10/24

                     

The DMZ is directly connected to the Router: 176.16.2.0/24

 

Finde attached the running-config of the router.

For Inbound calls one way

For Inbound calls one way call route is blocked.

See when an inbound call lands from 217.10.68.147 on outside interface of router (46.59.194.32) , the outside interface sends back trying and relay the second INVITE towards phone 192.168.21.10 but in that INVITE  it did not modify the telco ip (217.10.68.147) with inside interface ip (192.168.250.1). So the call reached at the phone and phone start ringing but when phone goes off-hook and sends a session establish message back to 217.10.68.147 , it did not reached to it as route from 192.168.250.1 -> 217.10.68.147 is blocked.

What you need to do is to convert 1941 router as a back to back agent. Configure  dial-peers with proper interface binding and enable the sip parameters. I think this will also resolve you outbound call issue.

New Member

Hi Manish, how do I do that?

Hi Manish,

 

how do I do that? The router do not support any special VoIP functionality.

 

Below the Phone config.

Which ios version is running

Which ios version is running on this router ?

New Member

Router1941#sh version Cisco

Router1941#sh version 
Cisco IOS Software, C1900 Software (C1900-UNIVERSALK9-M), Version 15.1(4)M5, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2012 by Cisco Systems, Inc.
Compiled Tue 04-Sep-12 15:42 by prod_rel_team

ROM: System Bootstrap, Version 15.0(1r)M16, RELEASE SOFTWARE (fc1)

This IOS do not support voice

This IOS do not support voice features , the option left for you to put your phone on a network from where it can reach 217.x.x.x ips.

New Member

Hi can I install another IOS

Hi 

can I install another IOS which supports Voice features on this Router, or do I need an additional license?

The IP 217.10.68.147 belongs to SIPgate.

New Member

Hi,does the IOS c1900

Hi,

does the IOS c1900-universalk9-mz.SPA.152-4.M6a provide the necessary featchers? If not which one do I need?

I think you need Ip Base or

I think you need Ip Base or SP edition or Enterprise edition to run voice on the router . Go to cisco feature navigator to check the ios version which support voice on this platform.
New Member

Hi,I just played a bit around

Hi,

I just played a bit around with cisco feature navigator but didn’t get a proper result. I don’t know for what fetcher I should look.

This router platform do not

This router platform do not support advance voice feature that i mentioned above.

New Member

Hi,I don't want to run

Hi,

I don't want to run advanced voice features, I just want simple and working SIP inspection on the Zone-Based-firewall.

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