You can't forget that UDP is a connectionless protocol and hence unreliable. It has no method of retransmission and/or mechanism for discovering dropped packets. The advantage being that it has much lower overhead than TCP and is highly flexible regarding payload types (sacrificing efficiency). Thus, it is very possible that packets are being dropped across the VPN and not being reported by the sniffer because there is no "session" information being included with the packets. The only way to truly measure packet loss with a UDP connection is to put a sniffer on both ends and make sure *all* packets that leave Site A, make it to Site B. UDP relies on upper layer protocols to manage retransmission and CRC checks - but when dealing with VoIP, by the time you figure out the packet was dropped, it's too late to retransmit.
Again, there's no way a single sniffer on one end of the link can measure packet loss for a UDP connection as it has no way of knowing session information (only Src IP, Dst IP, Port Pair). Have you investigated MTU issues on the link to avoid fragmentation? HTH, Aaron ________________________________ From: Benjamin Zachary - Lists [mailto:[EMAIL PROTECTED] Sent: Thursday, June 19, 2008 4:57 PM To: NT System Admin Issues Subject: RE: Increasing Sockets The pbx guy brought me a sniffer and told me @ 40% packet loss is occurring across the vpn, Im running perfmon in real time view with all tcpv4 activity Im showing 17 connection failures of 1303 active, 17 eastablished, 1541 passive and 38 resets. Nowhere near the 40% Im being told *ugh* ~ Upgrade to Next Generation Antispam/Antivirus with Ninja! ~ ~ <http://www.sunbelt-software.com/SunbeltMessagingNinja.cfm> ~
