Skype is a sneaky bugger, if I remember right it probes your network a little and decides on its best method to get through your system. It will do http-tunneling if necessary to operate, which is why it will work in most environments. ________________________________ From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Ara Avvali Sent: Tuesday, January 16, 2007 4:56 PM To: isalist@xxxxxxxxxxxxx Subject: [isalist] Re: IM port usage No sir. It is only one ftp, https and https rule allowed from internal to external. And of course http filter is enabled. Without firewall client, it doesn't even login. With firewall client, it logins and audio/video works fine From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Thomas W Shinder Sent: Tuesday, January 16, 2007 1:10 PM To: isalist@xxxxxxxxxxxxx Subject: [isalist] Re: IM port usage Hi Ara, Yes, but I suspect you have an "all open" outbound policy, so you don't even need to know what protocols are used. :) Thomas W Shinder, M.D. Site: www.isaserver.org <http://www.isaserver.org/> Blog: http://blogs.isaserver.org/shinder/ Book: http://tinyurl.com/3xqb7 MVP -- Microsoft Firewalls (ISA) ________________________________ From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Ara Avvali Sent: Tuesday, January 16, 2007 2:46 PM To: isalist@xxxxxxxxxxxxx Subject: [isalist] Re: IM port usage What makes me wonder is why skype work fine (audio, video) by just having the firewall client. And Microsoft's own messenger has to go this way. From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Steve Moffat Sent: Tuesday, January 16, 2007 12:40 PM To: ISA Mailing List Subject: [isalist] Re: IM port usage Incoming??...outgoing??? Both?? S...:-) From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of Jim Harrison Sent: Tuesday, January 16, 2007 4:19 PM To: ISA Mailing List Subject: [isalist] IM port usage In case you weren't clear on what a horrific mess IM is for the firewall / proxy admin, check this out... http://support.microsoft.com/kb/927847 Jim All mail to and from this domain is GFI-scanned.