Cisco 2811 as LAC

[Antonio_1_2]

Hi,

If anyone can help me with this problem please?

I use Cisco 2811 as L2TP access concentrator (LAC) in my network (pppoe sessions are forwarded via L2TP tunnel to LNS).

CPU usage goes up to 70% with only 30Mb/s traffic rate.

30% of CPU usage is due to IP input process. Is this normal? Does Cisco 2811 these packets (from pppoe sessions through L2TP tunnel) forward with process switching? CEF is not used for L2TP?

In L2TP specification I saw that as LNS Cisco 2811 can handle up to 30Mb/s of traffic.

Is this number valid for LAC as well?

Also on this 2811 there is one L2TP tunnel and aproximatelu 90 corresponding pppoe sessions.

Thanks in advance,

A.

[paolo bevilacqua]

Seems normal, if you want better perfomances get a G2 router. The 2811 is an just a branch lever router already 7 years old, not designed for hub use.

[Antonio_1_2]

Hi,

so forwarding of packets from PPPoE sessions via L2TP tunnels are done in proccess switching mode(on 2800 series)?

Is this valid also for 7200 series?

I have few small sites where I'm using 2811 as LAC and on large sites I have 7200 as LNS (which concentrates small sites).

I though that 2811 could handle up to 60Mb/s as declared in product sheet, because it is not cost effective for me to put 7200 on smaller sites

Thank you,

A

[Juan Perez]

Antonio,

ISR G1 routers (1800,2800,3800) were not designed to aggregate traffic/connections. 7200 routers and higher platforms are the ones designed to act as LAC, LNS DSL Agg devices. Both platforms will use CEF as the switching method.

Regards.

[Antonio_1_2]

Thanks,

A

[paolo bevilacqua]

You could try a 2911 or 2921 also. These are three or more times fasters than ISR G1.

Thanks for the nice rating and good luck!

[Antonio_1_2]

Thank you Paolo,

regards,

A