Jabber can't receive a call

[akramroot]

Hello All, 

I need your help please .

I have a cisco jabber is function well on MRA , and on local network without problem .

But when i connected jabber on VPN i have a problem i can't receive a call .

Senario : 

-Jabber on VPN can't call jabber on local network.

-Jabber on local network can call jabber on VPN.

What is the cause of this problem ? and how can i solve it ?

Thank you in advance 

Best regards

[Carlo Poggiarelli]

Hi,

Just some questions here.

What message do you receive on Jabber when you call some internal extension while in VPN?

Going on CUCM take a note of the IP address your jabber uses to register to the CUCM while on VPN and ask your security guys to dig firewall logs searching for your IP traffic.

Please let us know

Regards

Carlo

[akramroot]

Thank you for your reply , 

I tested with a jabber on shared line with a nother cisco ip phone , I will test to jabber without shared line and i tell you the message that i receive .

Best regards 

[collinks2]

why do you need vpn when you have MRA?MRA is simply less vpn solution to
allow remote users to login via jabber
you can still check NAT

[akramroot]

Thank you for your reply ,

I agree with you , but my customer inssist to use jabber on VPN.

Where can i check the NAT ? in the rules of the firewall ?

Best regards 

[Carlo Poggiarelli]

Hi,

@akramroot yes you have to check NAT rules on firewall.

@collinks2 Sometimes som customers need to go through VPN to reach enterprise applications not publicly reachable.

I know that it’s an old and in some case not really safe approach but it happens very frequently especially now that users and companies priviledges remote working.

Cheers

Carlo

[akramroot]

hi @ Carlo Poggiarelli

Thank you for your answer , 

This  NAT , rules must be disabled or enabled ?

Thank you in advance 

Best regards 

[Carlo Poggiarelli]

Hi @akramroot 

If your firewall is natting VPN clients traffic is doing something wrong with IP traffic.

Les't proceed checking  this.

- Go on CUCM Device Page and search for a Jabber connected through VPN.

- Note the IP address that you see as registering IP address for that Jabber

- Ask your security team if they can see dropped traffic for that IP Address

Can you please try what I asked before?

Please let me know

Regards

Carlo

[akramroot]

Hi, @ Carlo Poggiarell

Once I will be on site , i will tested  and i will inform  to you 

Best regards 

[akramroot]

Hi, @ Carlo Poggiarell

I tested the call it give me message busy  on ring back .

I found a deny tcp from my cucm to address ip where jabber registered on VPN.

Best regards

[akramroot]

Hi @   Carlo Poggiarell ,

When I applied UDP mode on jabber it worked again

Best regards

[Carlo Poggiarelli]

Hi,

That's why it didn't work while on VPN your firewall was blocking necessary tcp ports while it does not on UDP ports.

Glad you solved your issue!

Cheers

Carlo