Overview of Cisco Catalyst 3850 switch


As many of you will be aware, Cisco announced the release of the Catalyst 3850 switch at Cisco Live 2013 in London only last week. As I blogged at that time, this wasn’t the world’s best kept secret. Several people were talking about it online and I’d come across a few pages on different parts of Cisco’s website hinting that it was coming. There was mixed reaction to the news from ‘is this not just a 3750 with an integrated Wireless LAN Controller?’ to more warm and welcoming feedback. I’ll try and leave my own judgement until the end of the post but for now, let me list some of the specs of the 3850 and make the obvious comparison to the 3750X using data from Cisco’s website:

Comparison of Catalyst 3750-X and 3850 Switches

Features Cisco Catalyst 3750-X Cisco Catalyst 3850
Stacking bandwidth 64 Gbps 480 Gbps
Cisco IOS® Software wireless controller No Yes
Queues per port 4 8
Quality-of-service (QoS) model MLS MQC
Uplinks 4 x 1GE2 x 10GE NM4 x 1 GE or 2 x 10GE SM 4 x 1GE2 x 1/10GE4 x 1/10GE(on 48 port model)
StackPower Yes Yes
Flexible NetFlow support Yes (C3KX-SM-10G required) Yes
Multicore CPU for hosted services No Yes
Flash size 64 MB 2 GB
Operating system Cisco IOS Software Cisco IOS-XE Software

The first thing that is immediately obvious is I need to find a better way to format tables on my site!

The second thing is that, putting the integrated wireless functionality of the 3850 to one side for now, it is clear that the 3850 offers improvements in several areas; far greater bandwidth across a switch stack (where more than one of these switches are connected together as a single ‘virtual switch’. The actual stacking cables themselves are much improved too), more queues per port, a preferable QoS model and a move to IOS-XE which in itself has a number of improvements over vanilla IOS. Take a visit to various places on the web and you will find many more spec sheets that show improvements of all sorts e.g. more ACEs for security, QoS and PBR, a bigger TCAM and many more.

Integrated WLC

Whilst we all love having more of everything to play with on our favourite devices, I think that the feature that gives this announcement some punch is the wireless capabilities of the switch and all in a 1U form factor. You could also get this functionality in a 3750X but only on a 2U switch from what I recall. Of course, if you want to stack your switches and want redundancy in the WLC also, then 1U wins over 2U every time, 4U over 8U, etc.

The WLC integrated in to the 3850 has some features that you might want to see in any Cisco controller e.g. Clean Air, EnergyWise, QoS. One switch will support 50 WAPs and 2000 clients. Although I haven’t looked at purchasing these yet, I was told by a number of Cisco people at Cisco Live that the price is going to be comparable to a 3750X, but you will probably need to add on the WLC licencing to that base price.


If you consider that you are saving yourself the requirement for a standalone WLC on top of all of the increases in capabilities, the move to IOS-XE, the improvement in the stacking technology etc., the 3850 looks like a very capable and tempting upgrade to the 3750X. Cisco are classifying this product under Unified Access, bringing wired and wireless access in at the same point. I just wish I’d had the opportunity to put them in to our office network last year when I opted to use a pair of stacked 3750X switches with a 2504 WLC.

Till the next time.

5 Replies to “Overview of Cisco Catalyst 3850 switch”

  1. Pretty average that they cannot be stacked with 3750X’s. I was hoping that we could just add a 3850 to our existing 3750X stacks get get the wireless capability, I suppose I could always just etherchannel it. Considering they are the same price as 3750X’s, but offer a lot more features, people who have recently purchased 3750X’s will be very disappointed!!!!

    1. Hi Matt and thanks for taking the time to reply. I can’t immediately think of a stacking technology that allows different models. This restriction comes from what the stack is trying to achieve i.e. hardware redundancy and so an exact match is required. Agree on the price. Good news if you are looking now, bad news if you bought 3750s before hand and need the wireless capabilities in addition.

  2. You might mention that there is not currently a 3850 model to replace the previous fiber aggregation switches. This is quite frustrating as its apparent Cisco is nearing abandoning the 3750 line. There is a large number of people who utilize the 3750 platform as a collapsed core at small offices.

    Cisco has the opportunity to provide a single switch for large companies to standardize on for small branch offices. The 3850 could be used as the closet access switch as well as the Layer3 Distribution switch with LAN, IPBASE, AND IPSERVICES being available software options on the switch.

    If this could be done, we can now scale a facility from a single Router and Switch all the way to full Block Level Design without having to rerack hardware and hence recable at the facilities MDF. I can do the entire upgrade remotely and just have a field analyst rack and cable the new switches as the site expands.

    Previously Cisco has always had a Fiber Aggregation Switch:

    3508G XL

    I read in a posting on the CCO Forums that at this point in time they have no incentive to do this as the customer hasn’t requested it. We need to inform the customer as much as possible so we can all tell our Reps and get a Feature request put in.

    Unfortunately, we’re probably going to move away from the stackable platform all together and just use the 4500 series as the Business Unit behind the 3750/3850 has obviously missed the boat here by being so insistent on not even considering this as an option until next year. In my opinion, the 4506 bundle with the two 48 Port PoE+ cards is still a better deal for even access switches when you are putting in more than 2 switches. We just prefer the stackables due to the ability to scale to 438 ports as opposed to the 4510R’s 384 port limit.

    Well.. touché Cisco… Touché.

Please let me know your thoughts!

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