topic ASA 8.4 and Lync/skype for business client in Network Security

ASA 8.4 and Lync/skype for business client

SIMMN — Tue, 12 Mar 2019 05:56:25 GMT

This doesnot make much sense but maybe someone else can help me understand more.

We have user complaining (more and more) about Lync desktop presentation doesnot work when inside office. We have ASA 5510 running v8.4.6. Not the greatest version of the OS but does the job.

I checked ASA log while user tried to connect or present desktop, ASA most of the time doesnot bark but I did capture some UDP traffic drops (screenshot attached).

I did some research online and seems like I need to open UDP port 50000 to 50059 on external interface. Okey, so I did that even I prefer not to.

But desktop sharing/presentation is still broken...and now I do not see ASA drop anything either...

Interesting add-on, if both the viewer and presenter are behind ASA or one is behine ASA and the other is on Cisco remote VPN, there is no issue...

Please advise.

Anyone please?Am I the only

SIMMN — Tue, 19 May 2015 19:08:37 GMT

Anyone please?

Am I the only one run into this issue?

I have the same problem. But

Yvon Darang — Mon, 07 Nov 2016 13:10:59 GMT

I have the same problem. But my IOS version is 9.1.

Hey Shuai,

craigneeld — Fri, 09 Dec 2016 16:00:41 GMT

Hey Shuai,

Im confused. Your LAN (office based) users are having Desktop sharing issues and you have an internal ASA? Or are your users on a VPN? Do you have Edge Servers in your Lync topology?

Take a look this for call flows:

https://www.microsoft.com/en-gb/download/details.aspx?id=39968