... | ... | @@ -227,19 +227,21 @@ according to your hardware. |
|
|
??Author: Benoit Rat, [Seven
|
|
|
Solutions](www.sevensols.com??)
|
|
|
|
|
|
### Q: How fast is the overall performance within the WR switch fpga? Is it really 18\*1Gbps?
|
|
|
### Q: How fast is the overall performance within the WR switch fpga? Is it really 18\*1Gbps? As an example: When I establish a connection between port1 and port2 with 1 Gb/s is it possible for port3 also to communicate with port4 with 1Gb/s ? Is it still possible for each connection to communicate at full speed?
|
|
|
|
|
|
A: A good question. It should be and it is meant to be but it's not yet
|
|
|
possible. The current gateware have the following issues:
|
|
|
|
|
|
1. It cannot handle well 100% load (so 1Gb/s) traffic even if you have
|
|
|
only two ports connected, so if port1 talks with port10, only. It is
|
|
|
only two ports connected, so if port1 talks with port2, only. It is
|
|
|
ok up to ~90% of traffic load.
|
|
|
2. It has problems with handling small frames (\<128 bytes) at high
|
|
|
loads
|
|
|
3. If you use a large number of ports at the same time (as you
|
|
|
described), the forwarding performance drops (the load of traffic
|
|
|
that the switch can forward between each pair of ports drops)
|
|
|
3. If you use a large number of ports at the same time (more than 8
|
|
|
ports which create 4 pairs), the forwarding performance starts
|
|
|
dropping (the load of traffic that the switch can forward between
|
|
|
each directly connected pair of ports goes down as the number of
|
|
|
used ports goes up).
|
|
|
|
|
|
(as for July 2013, concerning v3.3 and below of gateware, intended to be
|
|
|
fixed for v4)
|
... | ... | |