Network Performance - 3850 vs. 2960

[Scott Hanson]

Hello everyone,

I have a network coming up for a switch refresh.  Management is pushing for 2960s and I would like 3850s.  We are running Cisco Voice and Video over the network.  I saw a few things that seemed to be in favor of a Layer 3 switch vs. a Layer 2 switch.  Some items like better performance due to switching based on IP vs. switching based on MAC.  Can someone point me in the direction of some information that will show the 3850 to be a better choice or that the 2960 is capable.

Thanks in advance!  All replies rated.                  

[Reza Sharifi]

Hi,

Have a look at these 2 links and compare the numbers.  As you already know the 2960 is just a layer-2 device and doesn't give all the layer-3 functions if you need them.

Here are some of the similarities and differences:

Both 2960 and 3850 can be stacked

3850 has 3 fans while the 2960 has one

3850 has 2 power supplies while 2960 has one

3850 can be power stacked while 2960 can not

3850 runs IOS-XE while the 2960 runs IOS

Overall, the 3850 has a lot more functionality, but I am sure 3850 is a lot more expensive the the 2960.

table-7 in this link

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps12686/data_sheet_c78-720918.html

to table-4 in this link:

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps6406/product_data_sheet0900aecd80322c0c.html

HTH

[Joseph W. Doherty]

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Posting

Actually for raw performance, MAC switching is generally faster than IP switching, although the latest L3 switching hardware comes very, very close.

Where a L3 switch, like the 3850 will shine, is that it offers IP routing, while many L2 switches do not.  (Later 2960s do offer limited routing.)

Unless you have a need for L3 forwarding on the device, justification of a L3 switch like the 3850, because of its additional cost, is difficult unless if offers some other features needed for your traffic.

Sorry, I realize my post is not what you're hoping for, but L2 vs. L3 is the big difference between the two.

[gneltnor]

To add to the debate, Cisco just posted some additional info regarding their up and coming 2960-X which appears to have IP Lite / Netflow Lite / additional power supply, etc:

Data Sheet

http://www.cisco.com/en/US/customer/prod/collateral/switches/ps5718/ps12995/data_sheet_c78-728232.html

Bulletin

http://www.cisco.com/en/US/customer/prod/collateral/switches/ps5718/ps12995/product_bulletin_c25-728262.html

There is a Live 365 event regarding this switch:

https://www.ciscolive365.com/connect/sessionDetail.ww?SESSION_ID=7628

[Leo Laohoo]

Scott,

You'll need to whittle your choices down ... a lot.

Bring your choices down to two models:  3850 and the 2960-X.

The 2960-X can be stacked to up to 8 switches in a stack and with a backplane speed of 80 Gbps.  I seriously would NOT recommend you stack a 2960-X with a 2960-S because the most you can do is four switches in a mix-stack of -S/-X.  Cisco will never allow anyone to buy one 2960-X and potentially stack up to 7 cheaper 2960-S.

The only way for you to sell 3850 to your management is when you have plans to roll out wireless.

You also don't know what "role" the 2960-X plays when the 6880-X/6807-X comes out this year. 

[Scott Hanson]

Thanks Leo.  We actually do have Cisco Wireless running.  WLC5800.  What are the advantages on teh 3850 with Wireless in the picture?

[Leo Laohoo]

The biggest advantage with the 3850 with you have wireless is when you transition from 802.11n to 802.11ac.  The 3850 will play a pivotal role in 802.11ac operation as MA/MC.

[Jason Horne]

Scott,

As Leo eluded to you can separate out the MC/MA functionality of the WLC.  You can still control the AP's and push down configs to them from your 5508 but instead you can now terminate your CAPWAP tunnel onto the 3850 itself.  This allows you to get the traffic onto the network sooner so that you can do things like leverage IOS ACL's onto your wired/wireless traffic, overcome bandwidth bottlenecks with terminating your traffic on the 5508 (8 Gbps) and stoping the traffic from going all the way to the WLC and then back down to the same AP when communicating with a local resource.  You'll see more of the MA/MC funtionality moving forward with the Enterprise line of Switches.  Look at the Sup 8E for the 4500E.