|
North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: MTU of the Internet?
At 10:17 AM 2/6/98 -0600, Stephen Sprunk wrote: >Does anyone have data to show if any terminal servers or client stacks >will honor TOS bits and/or known interactive port numbers when >ordering packets for transmission across slow links? This is relatively trivial with Cisco terminal servers, but it does have to be done manually. I'd be really surprised if no other vendor can specifically order packets in the queue by port number or something. Cisco does automatically take specific steps to allow smaller packets (regardless of TOS or port number) through the box faster when coming from many slow interfaces to one fast interface. The idea is, why should a bunch of (completed) telnet packets wait for the ethernet/T1 while a gigantic 1500 byte FTP packet is still serializing from a 28.8 modem connection? This should help "perceived" response times on interactive (e.g. telnet w/ 64 byte packets) stuff while not actually decreasing the throughput of large file transfers on other peoples' links. Supposedly, some other vendors place a packet in the outgoing queue when the first byte arrives. If you have a bunch of small packets come in (and complete) just after the big packet starts, you could create delays and waste bandwidth on the uplink. Of course, I've never actually measured the effects this, nor do I have first hand knowledge of how other vendors handle the process. I'm just taking Cisco's word for it (which you are more than welcome to disprove with real data - if possible ;). >Stephen Sprunk "Oops." Email: [email protected] TTFN, patrick ************************************************************** Patrick W. Gilmore voice: +1-650-482-2840 Director of Operations, CCIE #2983 fax: +1-650-482-2844 PRIORI NETWORKS, INC. http://www.priori.net "Tomorrow's Performance Today" **************************************************************
|