Hello!
What we have done was to take two GSR R1, R2, the appropriate interfaces,
configured a static routing loop between R1<->R2 and another Fastethernet
with a notebook flood pinging (under *BSD useinf the "-l" option) with TTL=
255.
With 1port GigE you see packet drops and a rate that is below MIN(1Gbit/s,
128*ping-bandwidth). A 1port GigE is not "wire speed" when your packets
are small enough.
The 3port GigE looked quite good with this test, down to small packets
(don't remember exact size, somewhere 40-100 byte per packet). But we have
tested only 1 or 2 traffic/ping flows and now all three ports
bi-directional.
The raw bandwidth to the backplane is 5 Gbit/s (4*1.25). Things are
somewhat complicated because the packet is sliced into cells with 48 bytes
payload (hmm ... I have seen this number somewhere before ;-) and 64 bytes
total size. So in worst case what might happen is
5 Gbit/s / (64 byte * 8 bit/byte) = 10485760 cells/s
(10485760 cells/s / 2 cells) * 49 bytes = (approx) 1.91 Gbit/s
in the case of IP packets with 49bytes total size, which is "only" 77% of
the 2.5 Gbit/s an engine2 is "promised" to deliver.
Regards, Marc
On Sunday, March 3, 2002, at 12:56 PM, Matt Ryan wrote:
> You need to define "wire speed" then. For example, the 3 port GE card
> requires 3G (easy math) of switch fabric capacity to the backplane, but
> there is only ~2.8G available. Therefore under 100% utilisation, this card
> it is not "wire speed" - Cisco will tell you it's oversubscribed.
>
>
> Matt.
>
> -----Original Message-----
> From: Greene, Patrick [mailto:pjgreene@infotechent.net]
> Sent: 02 March 2002 02:07
> To: Hank Nussbacher; cisco-nsp@puck.nether.net
> Subject: RE: [nsp] GSR GigaE pps
>
>
> You can expect full wire speed performance from all Gig ports on the GSR.
> I
> have tested this personally.
>
> Thanks,
> Patrick
>
> -----Original Message-----
> From: Hank Nussbacher [mailto:hank@att.net.il]
> Sent: Thu 2/28/2002 2:00 PM
> To: cisco-nsp@puck.nether.net
> Cc:
> Subject: [nsp] GSR GigaE pps
>
>
>
> I know that a GigaE interface on a 7500, even with a VIP4-80 will top out
> at 200kpps. Has anyone done benchmarks on GSR GigaE interfaces? What is
> the top value you have seen on the following cards:
>
> Engine 1: 1-Port GE w/ ECC
> Engine 2: 3-Port GE
> Engine 4: 10-Port GE
>
> Thanks,
> Hank
-- Marc Binderberger <marc@sniff.de> Frankfurt/Germany
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