[HECnet] OT Cisco question

[Mark Pizzolato]

On Tuesday, February 9, 2016 at 10:44 AM, Brian Hechinger wrote:
> I’m a huge fan of the ISR line as they tend to be cheap and have quite nice features.
>
> The big question is what routing bandwidth do you need.
>
> If you just want to route between DSL and LAN then just about any router 
> will do as DSL speeds are low enough.
> 
> If you want to route between LAN segments you will have to be pickier about 
> what models you are willing to consider.
> 
> As an example, the 1800 series routers (like the ones I’ll be sending to Steve 
> and Cory [and you Ian, I promise to finally send that one!]) route about 
> 70k PPS and 35mbit/sec.
>
> The 2851 I have at home that sits on the edge of my network can route 
> 220K PPS and 112Mbit/sec.

I had been very happy with the ISR line having bought a 2901 a few years back.
This past June my bookkeeper was ready for an upgrade at her site (the 
offered 851 came from there).  I took this as an opportune time to upgrade 
my ISR2901 to a new ISR4321 and migrate my existing ISR2901 to the 
bookkeeper's office.

At the time we were upgrading the internet links at both sites from 12Mbit 
cable service to 50Mbit cable service.  Hence the need for a device with more 
throughput.  The upgrade at my place came along first and I was getting 59Mbits 
on the service while paying for 50Mbits.  It was nice that Comcast rounded up
their rate limiting so I would have no basis to complain.  I then received the 
ISR4321 and got it running and deployed the 2901 at the Bookkeepers office.
The bookkeeper was now getting 59Mbits as well, however back at my office, 
I was only seeing 47Mbits with the newly deployed ISR4321.  In fact, I could 
still measure 59Mbits with the WiFi router connected to the same Cable 
modem.  I dig around and read the detail I had originally overlooked when 
I selected the ISR4321.  As it turns out, the ISR4321 comes with some built 
in software throttling which is rated at 50Mbits.  The measurements I've 
been quoting are speedtest.net measurements which I think are merely 
measuring TCP payload delivery rates and ignore the IP and TCP packet 
headers in the computation.  The Cisco 50Mbit rate limit includes all the 
bits on the wire and as such the 47Mbits of TCP payload was in fact the 
Cisco limit.  This rate limit can be upgraded to 100Mbits for an extra fee 
of $1000.  Needless to say I was not particularly happy.  The solution I 
came up with was to buy a used 2901 on eBay for about $800 and sell 
the lightly used ISR4321 for about $1200.  The 2901 is rated to go up to 
about 160Mbit/sec without any extra fees!

To repeat the previous offer, there are a Cisco 851 and Cisco 2620 routers
available for the asking for the cost of shipping.

- Mark