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Router Sizing

Hello Everyone.

I need some help sizing out a router for a project I am working on and thought I might be able to get some advice from the community.

Basically, I am connecting to organizations together via a dark fiber connection. At some point in the future, they want to be able to use the line for up to 1Gbps speed, but at the beginning, they are only going to be using 100-500Mbps. I was looking at the 3845 line of routers to use on both sides so that I can do some basic packet filtering to limit traffic coming into each organization (they are terminating into a DMZ but still want to limit what can go down the pipe). When looking at it, it looks like the 3845 only has 45Mbs of sustained throughput. Are there any network module cards that I can get or upgrade the router with to get up to 500Mbs for the initial deployment, then within a couple years upgrade to a larger router than will support the gigabit speed that is needed. We are trying to reduce cost for the initial deployment until the demand rises enough to warrant making the large purchase for gigabit routers. I thought about using some form of L3 switch, but that may not be sufficient since we need to do packet filtering on each side, but it may since the switch has ACL's for the vlan interfaces.

Any help you can give would be appreciated.




Re: Router Sizing

Re: Router Sizing

with the 3600/3800 series i dont think you will ever get the gig throughput you need. why dont you just go the the 6500's. perhaps you should terminate the dark fiber on cwdm and connected the 6500 to one of the channels on cwdm using a specific wavelength and then leave the other channels on the cwdm for future use so you dont need to think about scalabilty in the future or buying more equipments for upgrade.


Hall of Fame Super Silver

Re: Router Sizing

Hello Nick,

I agree with Francisco C3845 is too weak for this job.

you should go for a cisco 7301 or a cisco 7206VXR with NPE-G2 or a C6500 with SUP720.

Hope to help


Super Bronze

Re: Router Sizing

The 3845 is capable of more than 45 Mbps. Its Fast/CEF Switching performance is listed at about 500 Kpps (for 64 byte size packets). In theory, this should support 100 Mbps, duplex.

There are switch modules that will provide the raw performance you're looking for using ISRs, but I don't believe they will provide the combination of performance with all typical ISR featues.

In fact, it's often difficult to find high speed and full features without getting into some expensive equipment.

If your requirement for features are indeed minimal, you might want to again carefully examine the featue set of some of the L3 switches, such as the 3650/3750 series.

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