Latency/Packet Loss on ASR1006

Tue Dec 7 15:32:55 UTC 2021

On 11/26/2021 1:09 PM, Colin Legendre wrote:
> Hi,
>
> We have ...
>
> ASR1006  that has following cards...
> 1 x ESP40
> 1 x SIP40
> 4 x SPA-1x10GE-L-V2
> 1 x 6TGE
> 1 x RP2
>
> We've been having latency and packet loss during peak periods...
>
> We notice all is good until we reach 50% utilization on output of...
>
> 'show platform hardware qfp active datapath utilization summary'
>
> Literally ... 47% good... 48% good... 49% latency to next hop goes 
> from 1ms to 15-20ms... 50% we see 1-2% packet-loss and 30-40ms 
> latency... 53% we see 60-70ms latency and 8-10% packet loss.
>
> Is this expected... the ESP40 can only really push 20G and then starts 
> to have performance issues?
>
>

I haven't experienced that across about a dozen ASR 1ks. Though I just 
checked and we are not pushing any of our ESP's over 50% currently (the 
closest we have is an ESP 40 doing 18Gbps). However, I'm pretty sure 
we've pushed older ESPs (5, 10's, and 20's) to ~75% or so in the past.

Given the components you have, I would have expected your router to 
handle 40Gbps input and 40Gbps output. That could either be 40Gbps into 
the 6 port card [and 40Gbps out of the four 1 port cards] or it could be 
40Gbps input that is spread across the 6 port and 1 port cards [that is 
then output across both cards as well].

Despite other comments, I think your components are well matched. The 
only non-obvious thing here is that the 6 port card only has a ~40Gbps 
connection to the backplane so you cannot use all 6 ports at full 
bandwidth. I think this router is well suited to handle 20-30Gbps of 
customer demand doing standard destination based routing (if you're 
doing traffic shaping, NAT, tunnelling, or something else more involved 
than extended ACLs you may need something beefier at those traffic levels).