[c-nsp] ASR1001 vs 1001-X PPP

James Bensley jwbensley at gmail.com
Wed Feb 3 05:23:03 EST 2016


>> We have a number of older 7206 routers used in a LNS role (PPP/L2TP).
>>
>> As part of a network refresh we are looking to move towards the ASR1001 or
>> 1001-X. The datasheet shows both support up to 5Gbps throughput and 8k
>> subs.
>>
>> Is anyone able to confirm if 8k subs on a ASR1001 realistic in the real
>> world, or should we be looking at the higher CPU on the X version?
>>
>> Also on the throughput restriction is this in+out on all ports combined?
>> For example we have L2TP/PPP on one interface and upstream traffic on
>> another port. If we have 1Mbps of traffic coming in and then route out on
>> the L2TP/PPP interface is this counted as 1Mbps or 2Mbps?
>>
>> Thanks in advance.
>>
>> Ian

Hi Ian,

That should be fine however failure scenario wise are you planning for
8k sub's total aggregate across both boxes? If you want to go over 4k
sub's per box you might need to step it up a bit.


On 2 February 2016 at 22:38, Feedly Reader <feedlyreader at outlook.com> wrote:
> Hi Ian,
>
> Based on my understanding, the CPU on 1001-X is more powerful and can handle more concurrent session establishments. It also has 2 10G interfaces which can come in handy. However, the queue-count is considerably lower in the 1001s which makes QoS difficult, depending on your policies. I would recommend a 1002-X if you are looking at ASR 1K.


My experiance is to not use an ASR1002-X although that depends on what
you are looking for (if you want QoS for example its a no-go). See
this post I made yesterday to the Cisco BBA list:
https://puck.nether.net/pipermail/cisco-bba/2016-February/001464.html

Many things don't work, port-channels in general on the ASR 1000
series aren't great so either get more boxes and use 1G links per box
or get bigger boxes and use 10G links. I have some 1002-X's and use 2x
1Gbps ports and on each, and each 1g port has several sub-interfacaes.
The IP address of Gi0/0/0.123 is advertised as by RADIUS as an LNS.
The IP address of Gi0/0/1.123 is advertised by RADIUS as if it were a
seperate LNS, and so on.

QoS over port-channel is pony. And it seems that QoS support for the
ASR1002-X specifically is borked. See here:
http://www.cisco.com/c/en/us/td/docs/routers/asr1000/configuration/guide/chassis/asrswcfg/multilink_ppp.html#pgfId-1096305

Also see here (search for "model f" right at the end of the page)
http://www.cisco.com/c/en/us/products/collateral/routers/asr-1000-series-aggregation-services-routers/q-and-a-c67-731655.html

And here: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_mqc/configuration/xe-3s/qos-mqc-xe-3s-book/qos-eth-int.html#GUID-95630B2A-986E-4063-848B-BC0AB7456C44


If you want to offer basic raw internet connectivity or just chuck
users into a VRF it works fine. In terms of migrating from you old
7200 series routers I encountered a few trip-ups; FreeRADIUS was
dishing out Framed-Compression attribute (had to remove that, its not
needed anyway it was a default), PBR not support (got some old dirty
circuits that use it), under a virtual-template interface none of
these commands are no longer supported (no snmp trap link-status, ntp
disable, ppp timeout multilink lost-fragment, qos pre-classify).


Cheers,
James.


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