I don't really know what the overhead of that specific stuff is, but it's all part of a packet coming up the stack to the routing layer, and it has to be done per packet, so packet size is irrelevant to that. Using traditional routing techniques such as process or fast switching, the packet will be decapsulated to IP regardless of the underlying layers. I imagine that most of the framing work is done in hardware. Marc
John Green wrote: > > ""the routing decision consumes the bulk of the CPU > bandwidth, shovelling the rest of the packet through > is low-overhead."" > > say a router connects a between ethernet and Frame > Relay or between two dissimilar Layer2 networks. Then > the router would be stripping off one networks' layer2 > frame and replace it with the layer2 frame of the > other network where the packet is to be sent. Would > you call this low-overhead as well ? > I guess your example would be if the router were to > connect between same Layer2 networks ie say both > networks are ethernet. right ? just want to make > sure... > > --- Marc Thach Xuan Ky > wrote: > > Sam, > > I think the question is: what is your average packet > > size? Using > > process or fast switching I should think that the > > packet size is almost > > irrelevant to the router. I have benchmarked many > > PCs and NICs running > > certain routing software. On a PCI bus PC the pps > > difference between 64 > > and 1518 octet frames was in the order of ten to > > twenty percent, i.e. > > the routing decision consumes the bulk of the CPU > > bandwidth, shovelling > > the rest of the packet through is low-overhead. > > Marc > > > > sam sneed wrote: > > > > > > I noticed Cisco uses pps when they give their > > specs for routers, firewalls, > > > etc. What is the assumed packet size when they > > come up with these specs? > > I'm > > > planning on using 2 2621's in HSRP mode (getting > > default routes via BGP) > > and > > > need to be able to support a constant 10 Mb/sec > > and would like know if > > these > > > routers will do the trick. > > > thanks > [EMAIL PROTECTED] > > __________________________________________________ > Do You Yahoo!? > Yahoo! Movies - coverage of the 74th Academy Awards. > http://movies.yahoo.com/ Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39017&t=38956 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
