North American Network Operators Group|
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Re: why upload with adsl is faster than 100M ethernet ?
Hi, the network path is: |-(ADSL)--------\ customer/ --Edge_router---...---Japan Server \-(100Methernet)-/ So, from edge_router to Japan server the path is identical. > > There is something wrong with both scenarios. > > A 5 Mbyte file is 40 megabits. With overhead, it > should > transfer in about one-half second over a 100 Mbps > ethernet > connection and somewhat less than 30 seconds on a > 2Mbps > connection. Yes. But, for ftp TCP control real end-to-end transmission speed. I attached a monitor computer to our core router along the path between customer's site and server. Monitoring computer ping customer's site by targeting both ends of ADSL line and ethernet line. The measuring is scheduled 20packet per 20seconds, we also ping each hop address along the path to server. The result shows there is no packet loss along from monitoring computer to customer site, but packet loss increase at a special hop along the path to server in japan. So, we think the bottleneck is not inside our network. And, TCP connection between customer's computer and its server should be affacted by same bottleneck. So, the uploading speed should be similar (?), but it shows so much difference! > > Look for duplex mismatch or something similar. I disable autonegotiation of ethernet. So, there is no such situation. > > Oh! There's another WAN link in the picture! What > are the MTU > settings? Are the packets being fragmented? Iis a > firewall > blocking all ICMP somewhere including path MTU > discovery? the measurement is taken without firewall in customer site. And, no packet filtering is enabled inside our network. > > Note that this isn't exactly within the realm of the > NA(North American) > Network Operators Group, but the photons don't > respect political > boundaries so you may get appropriate answers here. Thanks for all your helps. To me, knowledge should be shared around world no matter where people live. Luckly, NANOG/RIPE and some other group open to the wolrd. regards Joe __________________________________________________ Do You Yahoo!? Log on to Messenger with your mobile phone! http://sg.messenger.yahoo.com