Information regarding Cisco ISR 4221

[Pablo Foppiano]

Hello everyone!

We recently bought a Cisco ISR 4221 and I need information regarding the "Performance 35Mbps" that is specified in the Model comparison chart here. What does the 35Mbps means? 

Thanks!

[Reza Sharifi]

Hi,

That is the default aggregate throughput for the router which is 35Mbps and can be upgraded to 75Mbps.

HTH

[vidahostkenya]

HI Reza,

I have a simlar issues, what do you need to do specifically so that the router can take in 60mbps. Is it a tweak in the settings or purchase some addiitonal stuff ?

regards

MOrris

[Joseph W. Doherty]

60 Mbps aggregate or 60 Mbps duplex? If the former, you need purchase a "performance" license, which will provide 75 Mbps. If the latter, you'll likely be able to obtain it via the "boost" license, which removes the performance, but the performance will then very much depend on the nature of your traffic and your router configuration. (NB: I've found the 4221 is documented as being able to forward up to 1.4 Gbps for IMIX traffic.)

https://fastreroute.com/cisco-routers-performance/

[Diana Karolina Rojas]

Hello Pablo,

This is the recommended maximum throughput/bandwidth for the router model to work properly. Do you need some specific information? 

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Regards,

[Pablo Foppiano]

There is something I can't understand, this device has two Gigabit ports, so, that means that I will never be capable of moving data in that speed, my communications will be capped to 35 Mbps, that's right? Thanks!

[Joseph W. Doherty]

Yes and no. You'll be able to send and receive frames/packets at gig, but sustain traffic will be capped at 35 Mbps (unless upgraded to 75 Mbps, as noted by Reza).

If you want a 4K ISR that can support gig (duplex) you need an upgraded 4451.

BTW, often small routers have Ethernet interfaces which the router cannot sustain. The "theory" has been an ISR will be "bottlenecked" by its WAN connection.

[Reza Sharifi]

For the life of me, I can't figure out why Cisco produces boxes with 35 or 75Mbps of throughput in this day and age when we have Verizon and Comcast providing 100Mb or Gig to homes and when we have Gigs and 10Gig access to the Internet for businesses use for a very low price.

All I can say is that Cisco is good at marketing.

HTH

[Pablo Foppiano]

Perfect, now I understood!

Thank you very much!

[Reza Sharifi]

Pablo,

I completely agree. These numbers are misleading. You might be able to sustain a 100Mb or so for a few minutes but if your business requirement and demand is to be able to sustain much higher throughput, this box will not do it. Sorry!

HTH

[Joseph W. Doherty]

"You might be able to sustain a 100Mb or so for a few minutes but if your business requirement and demand is to be able to sustain much higher throughput, this box will not do it. "

I'm unsure a 4221 will sustain 100 Mbps even for just few minutes. It's throughput is IOS capped.

The prior generation of ISRs' throughput varied very much depending on the size of the packets and the device configuration. A 1921 is documented of being able to push 2.77 Gbps and a 2921 at 3.37 Gbps. This for 1500 byte Ethernet and no extra config options. I.e. this is their very best possible performance, but not something you would ever see in the "real world".

Conversely, Cisco recommends the 1921 for only 15 Mbps and the 2921 for 50 Mbps - quite a difference! These recommendations, though, should almost always be obtainable.

What Cisco did with the 4K ISRs, they capped their performance such that it too can almost always be achieved.

Also understand, it's very difficult (and expensive) to provide gig or better performance with the feature richness of an ISR. Many small L3 switches will walk away from an ISR's performance, but an ISR offers features not found on most any L3 switch.