Priscilla, Thanks for the response. Any idea as to why the TFTP protcol over our WAN will run at 4k/sec and FTP at 165k/sec. I just figured that the smaller packet size of UDP would help. I also thought that UDP is connectionless and thefor requires no ACKS. Other sites on our WAN I can transfer large files via TFTP and they run at very good speeds. I'm just concerned about this one site. Any other ideas?
Tim > -----Original Message----- > From: Priscilla Oppenheimer [SMTP:[EMAIL PROTECTED]] > Sent: Thursday, October 18, 2001 1:23 PM > To: [EMAIL PROTECTED] > Subject: Re: Slow wan link. TCP traffic "ok", UDP not okay. Please > help! [7:23391] > > This list either filters my answers or mangles them. > > I'll make another try here. It it comes out mangled again, I'll post it > somewhere on my Web site when I have time. > > > TFTP is a trivial protocol running on top of a trivial protocol (UDP). You > > shouldn't expect it to have good throughput. > > TFTP uses a block size of 512 bytes. The protocol is a command/reply > (Ping-Pong protocol) with no windowing, flow control, etc. The protocol > looks like this: > > Write Request-> > > > > > > > > > If there are any problems, the application-layer TFTP notices a missing > ACK > and retransmits. > > FTP, on the hand uses TCP. It looks more like: > > SYN my segment (packet size) is 1500 > SYN ACK my segment size is also 1500 > ACK > > GET (FTP command), TCP receive window is 8,192 (or whatever)-> > > Hey All. I was wondering if someone could help me out with a problem i'm > >working on. It's very weird to me and I can't find any reason why this > may > >be happening other than possible a Queuing issue. Please comment. > > > > I've done some testing to show the response issues from > spikinisse > >to an auburn hills tftp/ftp box. When a 9 meg > > file is copied from one of the 6509's in Spijkenisse using tftp > we > >see a speed of 4k/sec (9041904 bytes copied in 2251.956 secs (4016 > >bytes/sec) > > However, when I ftp'd a 2meg file from a server in Spijkenisse > to > >the same server in Auburn Hills, I see a speed of 166k/sec (2024013 bytes > >sent in 12 > > seconds (166.12 Kbytes/s) Seeing as in Spijkinisse it is > >approximately 8pm and they have 4 E1's, there should not be an issue with > >over-utilization. > > It intrigue's me as to how a UDP based application (tftp) can > have > >such a ridiculously slow speed of 4k/sec and a TCP based application > (ftp) > >has an > > average speed (considering 4 e1's) of 166k/sec. > > > > Spikinisse has a group of E1's to the cloud and our site in > Auburn > >Hills has a full DS3 to the cloud. > > > >Spik is in the Netherlands, and Auburn Hills is in the US. Any more > >information I need to provide? > ________________________ > > Priscilla Oppenheimer > http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=23405&t=23405 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
