to the router, not to the end station or server. In many network protocols, there is no mechanism
for the router to pass that information to the server. DECnet and CLNS will, but they are not
common protocols. For DECnet and CLNS, you promote the FECN and BECN bits to the
Layer 3 protocol. Remember that the Cisco router cannot throttle back the traffic; only the end
hosts can. The protocol provides for end-host notification, and the router passes the notification
along. Where it doesn't, you can either drop or defer the packet. If you drop the packet, you
might as well transmit it on the off chance that the network will deliver it (because you will drop
it anyway). If the packet is deferred, you need to decide how long it should stay around before
it becomes "stale" and should be dropped from the queue.
switch and how the features were implemented. CIR is the "guaranteed" delivery rate, or
Committed Information Rate. The access rate is the physical port speed. Normally, Burst
Excess (Be) is the amount you are allowed to burst over CIR. The excess burst is like a highway.
The speed limit is 65 mph, but you have been told that as long as no one else is on the highway,
you can go 90 mph. So your CIR is 65 mph with an excess burst rate of 90 mph.
that it will always be able to sustain a rate of 128 Kbps for my PVC.
of 128 K. Some carriers mark all traffic above CIR as discard-eligible (DE) but still transport
all traffic up to port or burst speed if there is no congestion. However, other carriers allow you
to exceed burst above your CIR for a fixed length of time only and then throw away anything
in excess of your CIR. Still other carriers offer 0 CIR service, in which everything is marked as
discard-eligible and by definition is all Be, but allow you to send traffic at the access rate. The
only way to find out what your carrier allows is to ask the rep and to test your circuit after it is
installed to make sure what he has told you is true.
Loose, Strict, Record, Timestamp, Verbose[none]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.100.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/58/60 ms