[c-nsp] ASR902 vs ME3800X

[James Bensley]

On 25 March 2015 at 22:49, CiscoNSP List <cisconsp_list at hotmail.com> wrote:
>>
>> On 3/24/2015 3:06 PM, James Bensley wrote:
>> >
>> > Its 12MBs shared.
>> >
>> >
>> > James.
>>
>> Pardon my ignorance once again, but is this showstopper bad?  The
>> me3800x appears to have 352MB, so clearly a lot more, but IIRC older
>> switches like the 3560 had something like 2MB per ASIC. I'm assuming one
>> of the main reasons for buffers on a unit like this is the speed
>> disparity between 10ge and 1ge ports, unless you're planning to do a lot
>> of shaping (rather than policing) - is this correct?
>>
>
>
> Significant difference to the ME3600 (Which is 44Mb?) - Would like some real-world feedback from anyones thats used these(ASR920s)....any issues with micro-bursts/drops?(You would have to assume yes?)

12Mbps could be a bugger if you are doing any decent amount of shaping
and oversubscription...

We don't have the ASR920's in production yet they're still in the lab.
Where I am at though is that the ME3600/ME3800s wouldn't allow us to
over subscribe the shapers on a port. I raised it on this list and
with Cisco, after some investigation from them (they were very helpful
btw!) it seems that its a limitation of the code running on
ME3600/ME3800s and there is no interest on Cisco's part to to change
that.

On the ASR920 this seems to be "fixed" in that it will actually let me
enter the confguration to over subscribe port shapers where as the
ME's would kick back and error and reject the config, although I
haven't tested it yet.

For clarity an example would be taht we have a 1Gbps port on the
ME3600, connected to a carrier NNI. We have 10 customer circuits
coming in on different VLANs through this NNI. Each one is shaped to
100Mbps for example. When we add an 11th circuit to the carrier NNI on
an 11th VLAN we add an 11th class map to the NNI port policy-map to
match the new service instance to shape it to 100Mbps to then nest a
QoS policy under that. The ME's would kick back an error not lettings
us configure 11x 100Mbps shapers on the 1G port. The ASR920 is letting
me configured it.

The proof will be in the pudding!

James.