AS5300 CPU problems

[jalsovszky]

Hello!

We have an as5300 with 120 channels of DSP (C549) with IOS c5300-ik8s-mz.123-15.

At about 80-90 calls (VoIP->PSTN, h.323, g729r8) the CPU load rises to 99-100% and calls are failing.

We limited the number of calls for 70 and it goes well now, however it should be able to handle 120 channels.

At 70 calls we have:

Larry#show processes cpu sorted

CPU utilization for five seconds: 81%/62%; one minute: 76%; five minutes: 68%

PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process

145 12473632 1416480 8806 3.75% 3.83% 3.65% 0 CCH323_CT

5 2236628 153278 14591 3.27% 0.41% 0.29% 0 Check heaps

127 7930616 5452316 1454 2.63% 2.24% 2.13% 0 VTSP

67 5739604 481779 11913 2.23% 1.79% 1.65% 0 ISDN

47 11019744 11158236 987 1.75% 2.05% 1.96% 0 IP Input

131 3506512 4067699 862 1.27% 0.96% 0.94% 0 VOIP_RTCP

160 2137080 2757459 775 1.03% 0.67% 0.61% 0 ISDN L2 Process

120 1598744 371435 4304 0.63% 0.44% 0.39% 0 RADIUS

Larry#show processes memory sorted

Total: 95704928, Used: 25886892, Free: 69818036

PID TTY Allocated Freed Holding Getbufs Retbufs Process

0 0 217720 28936 9653772 0 0 *Init*

145 0 468963292 3979335384 3079792 6071212 832276 CCH323_CT

67 0 2632872288 4020202104 1944100 953680 0 ISDN

6 0 28478916 13014716 1855436 15404978 24214932 Pool Manager

129 0 765115124 697748936 1741160 0 0 Session Applicat

127 0 3524278488 3151267532 1248380 7132410 0 VTSP

80 0 1054992 188 1054804 0 0 SCTP Main Proces

Any suggestion what can be wrong? Please take a look for the attachment [configuration and shov version].

Thank you in advance,

Tamas

[Chester Rieman]

The call rate is more important than the number of calls. The 5300 can do about 2 cps, any more than that and it getts pretty busy. Since H323 and ISDN are the processes using most of the CPU, it sounds like your normal call volume is keeping this GW pretty busy, maybe time for a 5400? ;-)

[jalsovszky]

Hmm, you can be right! Isn't the call spikes feature for solving such problems?

I have:

call spike 10 steps 10 size 100

But maybe I sould try:

call spike 2 steps 10 size 100

according your 2cps limit. Do you think it can help?

Regards,

Tamas

[Chester Rieman]

Good explaination of the call spike command here:

http://www.cisco.com/en/US/partner/products/hw/vcallcon/ps2027/products_implementation_design_guide_chapter09186a00800c1a3e.html#1158732

It might help depending upon the traffic patterns but you still can't put 10 lbs of stuff in a 5 lb bag ;-)

[jalsovszky]

I checked call spikes/threshold/etc. commands already.

What is as5300 intended for than? I hear many voices that it is able to handle 120 calls.

The soulution would be to ask the terminating party to not send more than 2 cps?

Would an as5400 solve such problems? How many calls can we make with? What about HPX?

Thanks

ps: Is as5300 so bad?

[teodorgeorgiev]

Hi Tamas,

maybe Crieman is right. The AS5300 can handle 120 calls, the issue is if it can handle the call attempts per second. Get the h323 call generator tools for Linux and test it against your 5300 Cisco.

Why don't you put a simple Linux/UNIX server in front of the 5300 to limit the maximum number of sockets to 120 ?

[jalsovszky]

Hello Teodor!

That's a nice idea. However that would introduce many problems. Not easy to put any box before the gateway, another single point of failure, delay source, etc.

I like the idea behind 'call spikes' command. Right I'm going to try it.

If it doesn't help, we will think about as5400.

Is HPX version required or the non-HPX would be enough?

Tamas

[teodorgeorgiev]

Never used the call spikes command.

Indeed the SPF and delay source claims are funny :)

It will add *maximum* 1.5ms of additional delay.

For high capacity ISDN gateways, you might try Vegastream and Quintum CMS. Vegastream have quite powerful CPU.

[Chester Rieman]

5350/5400 has much faster CPU than 5300, HPX version is faster yet.

5300:R4700 CPU at 150Mhz, Implementation 33, Rev 1.0, 512KB L2 Cache

5350:R7000 CPU at 250Mhz, Implementation 39, Rev 1.0, 256KB L2, 2048KB L3 Cache

Cisco IOS Release 12.2(2)XB introduces the Cisco AS5400HPX universal gateway, which supports a higher performance motherboard than the Cisco AS5400 universal gateways. The high performance motherboard has an upgraded CPU and L3 cache.

[davidferguson]

As a direct replacement for an AS5300, this might be an overkill, but the new AS5400XM seems to be able to tackle a full 16 PRIs of voice calls.

We are using AS5400HPX too, but in our environment (G.711 only) with only 14 PRIs fully active, the CPU% hits 100%. Cisco say this is due to a limitation of the hardware.

I believe there's an AS5350XM too, but I have no experience with it.

[davidferguson]

As a direct replacement for an AS5300, this might be an overkill, but the new AS5400XM seems to be able to tackle a full 16 PRIs of voice calls.

We are using AS5400HPX too, but in our environment (G.711 only) with only 14 PRIs fully active, the CPU% hits 100%. Cisco say this is due to a limitation of the hardware.

I believe there's an AS5350XM too, but I have no experience with it.