Cisco Catalyst 9200 latency

[ivanjaram007]

Hello everyone,

I hope someone can help me with my query. I've been looking for a while, but can't seem to find info about C9200 latency, not on Cisco datasheets or any other third-party site or testing centers (I found info from an independent testing center, but from model 9300 upwards). One of our customers is very picky and demands this info. Any info will be greatly appreciated.

BR,

Ivan

[Leo Laohoo]

If the customer is demand of a low-latency switch, then Catalyst switch are not right for the job. 

For low- to ultra-low latency, look at Nexus family of switches.

[balaji.bandi]

Catalyst are Enterprise LAN switches, Low Latency Looks for Nexus 3K or 6K or 9K depends on budget

[ivanjaram007]

Hi everyone,

Big thanks for a swift response. Unfortunately your answers did not answer my question. All I wanted to know is the value of latency as this seems to be pretty much the only thing non-existent on any datasheet regarding C9200. The customer wants to know the exact number as he is currently weighing options between Cisco and Aruba switches, where Aruba has latency clearly presented on its datasheets.

BR,

Ivan

[balaji.bandi]

basically Cat 9200 is basic Layer 2 switch part of Access switch deployment. unlike Cat 9300 can be deploy different modes.

i would have asked in the first place, what kind of Latency information you looking for ? are you a partner or end user of Cisco. if you are partner, check some partner tools may find that information (not that i am aware available)

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-9200-series-switches/nb-06-cat9200-architecture-cte-en.html

check other archtecture :

https://www.ciscolive.com/c/dam/r/ciscolive/us/docs/2019/pdf/5eU6DfQV/TECARC-2900.pdf

[ivanjaram007]

Hello Balaji,

I was thinking something like the snip from Aruba 6300 datasheet below:

Average Latency (LIFO-64- bytes packets)

1Gbps: 1.99μSec 10Gbps: 1.49μSec 25Gbps: 2.85μSec 50Gbps1: 2.82μSec

1Gbps: 4.24μSec 10Gbps: 1.50μSec 25Gbps: 2.91μSec 50Gbps1: 3.49μSec

1Gbps: 4.24μSec 10Gbps: 1.50μSec 25Gbps: 2.91μSec 50Gbps1: 3.49μSec

1Gbps: 2.28μSec 10Gbps: 1.46μSec 25Gbps: 1.90μSec 50Gbps1: 3.49μSec

Just so the customer can have a visual representation.

BR,

Ivan

[Leo Laohoo]

What is the customer expecting to connect to these switches, PC/Phones/Printers or servers?

[Joseph W. Doherty]

Cannot say for sure, as generally, unless you're interested in (or require) such low switching latency, you would normally only consider internal switch latency if the switch also supported cut through switching, because w/o that, waiting to receive the whole frame, before it can be forwarded, contributes to latency the same on all switches.  (I.e. a standard part of switch latency depends on the wire speed and the frame size.)

If you discount frame reception latency time, most switches are going to switch the frame within a few microseconds (which seems the case of the Aruba stats you published).

If it truly matters whether switch latency is 1 microsecond vs. 3 microseconds, then again, you'll likely be interested in cut through switching too, and on such switches, switching latency more likely to be published.

Also again, Cisco might not publish "typical" LAN switch's internal latency.  Possibly their pre-sales might be able to obtain such data.

[David Nolasco · Accepted solution]

Hi,

The info you are looking for is here:

L2 Performance

IPv4 Performance

The tables are specifically for a 9200L-24P-X. There are tables for each type of model and also for IPv6 performance and Multicast performance. I would suggest to get in touch with your Cisco representative to get all the details per model.

Hope this helps.

David N.

[ivanjaram007]

Thank you very much for this table, I sure hope that our customer finds it satisfactory. Cheers and best of luck!