Allowing VoIP communications between 2 SSL VPN users

[sbano]

Dear all:

I am currently implementing Cisco Jabber in our environment. It is a collaboration software allowing end users to make VoIP calls between them, share their screen, share their camera, chat, etc. I have been able to successfuly implement Cisco Jabber communications between (i) a given FortiGate SSL VPN user and (ii) a given user connected to the Corporate LAN. To this end, I am using FortiGate SIP ALG feature for Cisco Jabber VoIP communications. This works fine and is good from a security standpoint since RTP pinholes are being used. So far so good.

However, I am now running into issues when trying to allow Cisco Jabber communications between 2 SSL VPN users.

SIP traffic seems to be fine as Jabber of both SSL VPN users can receive / make calls. However, VoIP is not working as expected: only one user is hearing voice. When I run a diag sniffer on the FortiGate, I see that UDP (RTP) traffic is being sent to both VPN users.

Anyone had success in implementing Cisco Jabber (or equivalent for example Skype) between 2 FortiGate SSL VPN users? Am I missing something obvious here? (e.g. maybe there is a VPN feature to disable client-to-client communications but in that case why do we still have voice received by one use?) 

Many thanks in advance for your help.

Kind regards,

S. Besson

[lindseynicole010]

thanks