[c-nsp] ISR 4451-X route table size

Lukas Tribus luky-37 at hotmail.com
Wed Jan 14 20:06:05 EST 2015

> On Wed, Jan 14, 2015 at 05:52:43PM +0100, Lukas Tribus wrote:
>> Its a software router (similar to ASR1k),
> That's the first time I've heard someone call the ASR1k a "software
> router"... *raise eyebrow*

The ISR44xx series certainly is, with "multi-core data plane forwarding",
an "emulated QFP" [...] delivering "ASIC-like performance" [1].

As for the ASR1k, QFP based forwarding just never felt that "hardware"
to me. It only works through massive parallelization, packets are passed
to a free PPE thread which "runs through a feature chain in software" [2].
Of course some/a lot of steps in the packet forwarding process are
hardware assisted, but does this make QFP a real hardware based forwarding
engine? I don't think so.

Perhaps the software- vs hardware-forwarding distinction is just becoming
obsolete with those platforms, as the technical reality is somewhere in


[1] http://www.cisco.com/c/en/us/products/collateral/routers/4400-series-integrated-services-routers-isr/data_sheet_c78-728190.html
[2] http://www.cisco.com/c/en/us/products/collateral/routers/asr-1000-series-aggregation-services-routers/solution_overview_c22-448936.html


More information about the cisco-nsp mailing list