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0xc0040017 FWX_E_TCP_NOT_SYN_PACKET_DROPPED - 22.Jun.2007 6:18:30 AM

Revelston3

Posts: 1
Joined: 22.Jun.2007
Status: offline

We have an ISA 2006 EE array with 2 ISA servers. We have 4 networks, all load balanced, Internal, Wireless LAN, External and voice. We have just put in a new 'phone system, using IP, and have put that on its own network, the voice one. We have set up rules to allow PCs to communicate with the 'phone switch, so that users get pop-ups when their extension rings, and can use the PC to get their 'phone to dial, etc. All this is working perfectly. There is also a facility to use a microphone & headset on your PC, with a softphone client, but when we do this we hit a problem. It appears to work correctly, you can dial, etc, but there is no audio. Looking on the ISA server lots of the packets coming from the 'phone switch are being dropped with a 0xc0040017 FWX_E_TCP_NOT_SYN_PACKET_DROPPED error. I am guessing that these packets are actually the audio, and the ISA doesn't like them for some reason. How can I persuade the ISA array that it is OK to let this traffic through?
Thanks.

Post #: 1

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RE: 0xc0040017 FWX_E_TCP_NOT_SYN_PACKET_DROPPED - 26.Jun.2007 2:53:09 AM

alex3299

Posts: 44
Joined: 19.Mar.2003
From: Portugal
Status: offline

Even if the traffic refer to a Allow traffic rule, ISA will drop it, because there is no sychronization between the incoming and the outgoing packet.
Test the application on a lab, analyse the traffic with network monitor, set rules on isa, and when you get it working deploy it.

< Message edited by alex3299 -- 26.Jun.2007 2:58:20 AM >

(in reply to Revelston3)

Post #: 2