Need help with complex ATM network

[azev]

Currently we have an existing OC-12 backbone using marconi switches (asx1000, asx1200).
Most of the backbone switch have an available OC-3 to provice link to access switch.

We are in need of a powerfull router/switch that can convert ethernet to atm and throw the data to the OC-12 ring. We are thinking of getting a couple of cisco 3660 with an OC-3 module (connect to the uplink) and ethernet switching module.

My question is;
- how much ethernet bandwidth does it take to saturate an OC-3 uplink ?
- When you install a switching module on a router, does the module becomes a L-3 switch?
- We have equipments that will saturate the ethernet swithing module with tenth of thousands of small packets per second. Will a 3660 have enough CPU power to do the conversion ?

Thanks

 

[spidey07]

A router is a layer3 device, but not really a layer3 switch. You will abosultely kill a 3660 trying to do what you're requiring.

I'd call the manufacturer directly for this application. This is not an easy request and is normally handeled by optical switching gear - cisco 15000 line.

 

[azev]

wow, we are totaly limited by our budget. We are hoping to get a switching gear or a midsize router to do this for us. Right now the conversion is done via another marconi (fore-runner ES-3810), but we are killing this switch by just a couple of our equipment (cpu util is over 85%). The equipment we are using is IP Tube which convert a T1 into UDP ethernet. The downside of this, the IPTUBE is transmitting an insane amount of packets to keep the T1 link active. We going to transfer around 40T1 lines this way.
Any more ideas ?

 

[spidey07]

Originally posted by: azev
wow, we are totaly limited by our budget. We are hoping to get a switching gear or a midsize router to do this for us. Right now the conversion is done via another marconi (fore-runner ES-3810), but we are killing this switch by just a couple of our equipment (cpu util is over 85%). The equipment we are using is IP Tube which convert a T1 into UDP ethernet. The downside of this, the IPTUBE is transmitting an insane amount of packets to keep the T1 link active. We going to transfer around 40T1 lines this way.
Any more ideas ?

Please seek professional design assistance. Please.

There are people out there that can help this mess.

 

[azev]

what is the point of seeking for help, if they (the so called proffesional) only going to say "get a GSR or Juni M20"?

 

[cmetz]

azev,

1. It takes 155Mb/s of traffic per direction to saturate an OC3c. ATM overhead chomps a good bit of that away, though.

2. No. Completely apples and oranges.

3. Nope. Ciscos are notoriously underpowered, and the PPS rate of the forwarding engine is pretty much always one of the issues.

Cisco *claims* the 3660 can do 120Kpps fast path / 12Kpps slow path in the 3660 data sheet. I'd take that cynically, but you can probably get 10Kpps to work, you just need to be absolutely sure the features you need are available on the fast path (hint: don't use any features). I believe the ATM SAR is actually in hardware on the line card and won't slow you down. That said, I remember looking into ATM on the 3600 series and being steered away from it by Cisco's sales folks, which leads me to believe it's a bad place. I'd strongly urge buying gear from somewhere that will let you send it back if you can't make it work.

A 7200 would probably be a lot more suitable to your application.

This would be a routed (L3) solution, not a bridged (L2) solution. Bridging over ATM is typically something like LANE, which by pure coincidence rhymes with pain.

azev, why are you carrying T1s inside UDP over IP, which you then want to route onto an ATM over SONET? This is bass-ackwards. You need a SONET ADM.

 

[spidey07]

Originally posted by: azev
what is the point of seeking for help, if they (the so called proffesional) only going to say "get a GSR or Juni M20"?

Because they can help with your overall design. You're carrying T1s over UDP?????

Why?

 

[azev]

Trust me, it does sound very ackward, we have our reasons converting T1 into UDP because there's no other way we can accomplished what we need. We are sure of it, and believe me, we have alot of engineers working on this project. Anyway, everything is working well, but we cannot get anywhere near the capacity that we needed. Unfortunately we dont have the budget to get an expansive cisco router like the 7200 and up. Right now, I am researching for the best bang for the bucks until we roll out a new infrastructure. Btw we are dong LANE.

 

[Smilin]

Originally posted by: azev
what is the point of seeking for help, if they (the so called proffesional) only going to say "get a GSR or Juni M20"?

Because then you will know to get a GSR or a Juniper m20.

It sounds like what you really want is someone to lie to you about what you need so that you can get yourself into some sort of predicament by doing things half-assed. If you want big toys, they cost money.

 

[bgroff]

Azev -

The price difference between the 3660 and 7200 isn't as great as you think it is. You'd be looking at paying a 3-4k premium for much more horsepower. But like spidey said, you REALLY need professional assistance if you're asking the kinds of questions you're asking. If you go the 3660 route, you will have problems and the thing will take a dump on you.