Cisco Routers With LAN Extension Services

[robertsavage]

I work for a small Building Society which has a head office and four branch offices (all within a 5km radius). We currently have 64kb kilostream circuit connections between the head office and each of the branch offices (with ISDN lines to provide resiliance and 'topup'). We are looking to replace the kilostream lines with 10mb Lan Extension links (known as LES10 aka Short Haul Data Services - SHDS). We could implement LES10 without any routers as it provides an ethernet connection which can be plugged directly into a switch or hub. However, we still require the ISDN lines to provide resiliance in case of failure of the LES10 links. Thus, we still require routers to connect the LES10 and ISDN links to the LANs at each office.

We currently have Motorola routers (a 6520MPR at the head office and Vanguard 320s at the branch offices) and have been informed that these will not handle the throughput of the LES10 connections. BT (who proposed the LES10 solution) have proposed the deployment of a Cisco 2610 at the head office and Cisco 1605Rs at the branch offices. However, speaking to the company who provided us with the Motorola kit, they informed me that they doubt whether the Cisco routers proposed by BT can handle the 10mb throughput (40mb throughput required at the head office). You probably realise from the above that I am not a network expert and as such I would be obliged if anyone has any comments on the above. Ideally (from a cost point of view) we would like to run the LES10 solution and retain our existing routers for use with the ISDN lines but I don't know whether is feasible.

[karl.jones]

I agree, 1600 routers will definitely not handle 10mb of throughput for the LAN extension. You would probably be ok with 2620's at either side which have a good size processor 50mhz, built in ethernet and wic slots, and network module for expansion. If you "definitely" need 40mb of throughput then I would use 3640's where this bandwidth is required. This should be ok. 1600's definitely not a good idea.

HTH

[svermill]

I don't know anything about LES10, but I question whether or not you *need* 10 Mbps of throughput. Did your throughput requirements really go up by a factor of over 150? You are using a 64 kbps line now is my point. You need to analyze your network traffic to size your connection/throughput - not the other way around.

[robertsavage]

We have selected the LES10 option mainly due to cost as we are saturated on the current 64kb links and do need to upgrade them. When we were investigating alternative solutions the majority of potential providers proposed upgrade the kilostream circuit to a higher bandwidth, but in terms of cost this was a lot more expensive than the LES10 option e.g. the rental costs for a 512kb kilostream circuit are double those of the LES10 connection. In terms of our bandwidth requirement it is no where near 10mb per link (at the start of the project we were looking at 512kb links as ample). However, if we implement LES10 we obviously want assurance that we can run at that bandwidth if required (with the advent of technology like voice over IP who knows what bandwidth we may require 5 - 10 years down the line).