3825 or 2800 series ? Any advice..?

What are your in-house routing requirements? What are your security requirements? For example, will you be needing to create a DMZ? Will you be wanting VPN access from home or travelling users? Will you be using multiple subnets locally and wanting the device to route between them?

Is the implication that you might be wanting to go up to 4 external offices? You say that, "Max network bandwith usage will be

2Mbit", but does that include after the expansion to 4 offices?

What is the expected lifetime of the devices? Around here, it is getting to the point where a commercial DSL line as slow as 2 Mb/s has to be special ordered, so you should plan for bandwidth inflation over the device lifetime.

2811: 120,000 pps (@64 bytes), 61.44 Mbps 3825: 350,000 pps (@64 bytes), 179.20 Mbps

Thus neither of them should have any difficulty at all in keeping up with 2 Mb/s, or even 4 x 2 Mb/s.

However, if you start using the routing capabilities in-house, expecting to route 100 Mb/s to 100 Mb/s, then the 2811 can only do about 30% of full-duplex at those rates, whilst the 3825 would in theory be able to do 90% of full duplex at those rates.

Hey Walter, Thank you for your reply. By saying 2Mbit I meant the connection to each branch office.

A - 2mbit -> B A - 2mbit -> C

etc.

Actually Yes, I am thinking to use VPN for client access and DMZ etc.

Hi,

I would advise you to go for the 2800-series. The 3800's are overkill for your scenario. The 2800's are easily capable of handling the 4 DSL circuits and even come with hardware based VPN encryption on-board so you don't need to worry about the encryption load. About the remote offices; I'd suggest you to have a look at the 850 or 870 series routers. They offer great performance and functionality for such small branches. (don't know if they're G.SHDSL capable though).

If you'd need internal routing (as walter is mentioning), consider adding a layer-3 switch, which is cheaper and faster.

Erik

and if you do run out of connections/ capacity, you can add another router or upgrade then - you could move interfaces between boxes since net modules and WICs are supported on 28xx / 38xx

routers like most computer gear follow "Moores law" and get cheaper / faster with every new model - so it doesnt make much sense to buy lots of spare potential capacity unless you are likely to need it.

when the 28xxs came out, Cisco tried to characterise each model as "enough" capacity to handle a set of circuits with some of the more CPU and prossor intensive functions turned on

AFAIR 2811 is supposed to handle 2 * 2 Mbps, full duplex, worst case packet sizes, with VPN encryption, QoS, Voip, NAT and intrusion inspection all at thesame time - in practice this means a lot of spare capacity for the config you are discussing.

"routers like most computer gear follow "Moores law" and get cheaper / faster with every new model - so it doesnt make much sense to buy lots of spare potential capacity unless you are likely to need it."

You are right on the point. There is thin line between, investing in the "actual" and "potential". Sometimes making the correct "cost effective" decision is a bit trivial.

But I think I will go with 28xx and moving the IC's to a more advanced model over the time will be OK for me.