7204's running slow over DS3

[kitchej]

Here's the equipment. A pair of 7204 non-VXR w/NPE-200, 128MB DRAM, IO-FE and PA-MC-T3. I'm setting up some lab tests and need to pass Ethernet traffic over various T3 configurations hence the MultiChannel T3 card. So far using a full DS3 and depending on configuration (routing vs. bridging) I'm getting maxed at somewhere between 11 and 22 MBit/sec with routing actually beating out bridging. CPU utilization is always smacking around in the low 90% area when passing traffic.

Am I out of luck with the NPE-200's and need a serious bump in processor speed or am I configuring these puppies the wrong way? Other posts seem to indicate that these routers should be able to handle a DS3 and a fast-ethernet port.

Thanks in advance.

Jim

 

[BuckWeet]

Do you have IP Cef enabled, or route-cache turned on??

 

[kitchej]

I've tried it both ways when I was set up for IP routing. It didn't make a lot of difference, maybe 1.5 Mbit max. Just in case your were wondering I've also verified that traffic is fairly balanced among all DS1's. They all stay in the lower half of their maximum rate.

 

[BuckWeet]

Hrm, thats rather weird... I'm not that familiar with the NPE-200, but i would think it could handle a DS3.. Heck a 3640 can handle a DS3 (as long as you're not doing too much advanced routing)

You might check forums.cisco.com


BuckWeet

 

[jeter]

Have you looked into IMA?

“Reserve your right to think, for even to think wrongly is better than not to think at all”

Fisher CCNP,CCNA Network+

 

[vipergg]

It's certainly possible you are running into a bottlneck if you are trying to feed this off a 100 megabit line into a DS3 . Do you see a lot of buffers being swapped out on the serial lines ? I don't know what the specs are on your equipment , would probably start with that before getting too involved specially if you are sure you have fast switching of some type turned on all interfaces .

 

[mtashiro]

Do you have any ACL's on the interfaces?

You should be running cef with no ACL's. When you have ACL's you put the router into process switched. The max that the 7200 with that NPE is around 10Mbps.

 

[kitchej]

Thanks to everyone for all the assistance!

I can't say that I've looked at IMA because I'm unfamiliar with this term. As far as looking at buffer swapping on the serial lines, I'm not sure how to do this either. I've never had to use more than 2 T1's on a router before so jumping into a full DS3 is a radical change for me.

I've configured all 28 DS1's to be in a single multilink and then use the multilink to either route or bridge to the IO-FE port. Would this be the proper method to combine the DS1's? If not, what is a better (faster) way to be able to run between 8 to 28 DS1's?

I'm not configuring ACL's or have any other filtering in place so this should not pose a problem. I have used CEF and had route-cache enabled but with no significant changes in routing speed.

I don't know if running the multichannel DS3 interface (PA-MC-T3) versus a clear channel DS3 requires a faster router engine but the vendor that supplied the routers to me didn't feel that it was necessary to upgrade the NPE-200's.

 

[BuckWeet]

I was talking to one of the folks in our Core network group who has experience with the NPE-200's.. He was saying it would handle a DS3 easily...


Would you mind posting the configuration?


BuckWeet

 

[baddos]

post "show interfaces

 

[kitchej]

Sorry that it took me a while to get the configuration from one of the routers. I was called in for jury duty and got sworn in on a criminal case. Here's the config from one router. I deleted the unnecessary stuff to keep the post short. Baddos, unless the case goes into early deliberation, I'll get the routers running this Friday and post the interface statistics. Thanks everyone for taking time to look this over for me.

ip subnet-zero
!
ip cef
!
call rsvp-sync
!
controller T3 4/0
cablelength 0
idle pattern 0x10
t1 1 channel-group 0 timeslots 1-24
**** Other channel groups are configured the same
t1 28 channel-group 0 timeslots 1-24
!
interface Multilink1
no ip address
ppp multilink
multilink load-threshold 1 either
multilink-group 1
!
interface FastEthernet0/0
ip address 10.10.10.252 255.255.255.0
duplex full
!
interface Serial4/0/1:0
no ip address
encapsulation ppp
ppp multilink
multilink-group 1
!
**** Other DS1's are configured the same
!
interface Serial4/0/28:0
no ip address
encapsulation ppp
ppp multilink
multilink-group 1
!
ip classless
ip route 0.0.0.0 0.0.0.0 FastEthernet0/0
ip route 192.168.100.0 255.255.255.0 Multilink1
no ip http server
ip pim bidir-enable

 

[BuckWeet]

Why don't you just configure it as a clear channel ds3? Is that even possible on that module?

The problem is you're running PPP Multi-Link.. This sucks up processor resources for the load balancing across the links.

PPP isn't the choice for links over a few Mbps..


BuckWeet

 

[kitchej]

BuckWeet

The PA-MC-T3 is a multichannel T3 controller without clear channel capability. This was necessary as the routers will be used in various planned configurations using up to 14 DS1's. Is there another way to configure more than 10 DS1's (as virtual serial ports) and get full bandwidth? Barring that, any ideas on what NPE I need to use to multi-link at least 14 full DS1's?

Thanks,
Jim

 

[BuckWeet]

Can you just put them in a big channel group?

or does it limit you to 24 channels at a time?

 

[kitchej]

Yup, only 24 channels max. I'd already tried that and a channel group on this card logically spans just a single DS1. I tried to lump a bunch of DS1 into a bridge group but that stops at 10 maximum. Rats!

Do you know if an NPE-300 could handle the load running multi-link ppp? I'll try and talk our supplier into an upgrade if it can.

 

[BuckWeet]

PPP multi-link isn't built for high speed connections like that...

let me look around and see if i can find something

 

[BuckWeet]

http://www.cisco.com/en/US/products...s_configuration_example09186a0080093c71.shtml

interesting read.. basically what you want to do, there is no industry standard, but that module supports what you want to do.. and least what i assume you want.


BuckWeet

 

[kitchej]

So close! No problem with the IOS but the multichannel modules we have are single T3's and only the dual versions support the option. Arrgh! I took a look at the controller configuration and there's definitely no option there.

BuckWeet, Thanks for digging so deeply into this one.

Jim