Cisco ISR 2821 problem IPTV

[cyberurmel]

Hi @all,

shortly information due to the setup:

ISP -> PPPoeModem-> cisco2821 int Gi0/0 ->out int Gi0/1 to CiscoSg300 in L2 Mode -> One port IPTV Receiver

The Gi0/0 is splitted in 2 Vlans as provider have one for TV and one for Data.

Everything works fine except one issue : from time to time the TV screen stopps for a period from 1-3 seconds . Also i can reproduce this if i am connected via ssh and do a sh run command ..then the screen sucks too..not for long but its visionable.

I cant see any drops on Interfaces, also set everything to IGMP3 , enabled IGMP snooping on the L2 device , no high CPU at all. Enabled cef .

so perhaps someone could help me to find this issue. Please tell me which output you need. Ah it works before without issue directly on a Fritzbox connected which is replaced by the devices above.

Cabling is Gigabit (IPTV is 100Mbit ic) 

Thanks and Regards

Stef

[Philip D'Ath · Accepted solution]

I would check for speed/duplex errors first, and look for any increasing interface errors.

Next I would check that the 2821 is using a gold star release of code, such as 15.1.4M12a.

https://software.cisco.com/download/release.html?mdfid=279120798&catid=278875243&softwareid=280805680&release=15.1.4M12a&relind=AVAILABLE&rellifecycle=MD&reltype=latest

[cyberurmel]

Hi Philip,

thanks first for your helo. I triggered correct answer but it was a misstake by me.

Issue still persists.

I have the newest IOS (C2800NM-ADVENTERPRISEK9-M), Version 15.1(4)M12a, RELEASE SOFTWARE (fc1)

Also checked the speed ..is negoiated at 100Mb what is correct for the Receiver.

No errors on the uplink to the Switch where the Receiver is except of some drops

 13422 unknown protocol drops

Also the port from the switch uplink to Router has :

Receive Statistics
Total Bytes (Octets):	602600113
Unicast Packets:	62398186
Multicast Packets:	765033744
Broadcast Packets:	2041
Packets with Errors:	9

The Receiver port has 1 error. So it seems all ok. It hangs only sometimes for a second or 2 and then differencly up to 15 min till the next short outage.

Any ideas??

Thanks and Regards

[Philip D'Ath]

What sort of bitrate is used for the TV?  Are you using "ip cef"?

You could also try specifying "hold-queue" under each interface.  Try a value of maybe 200 to begin with.  If that doesn't make a difference try double it a few times.

[cyberurmel]

Hello Philip,

thanks for your help. What do you mean with Bitrate? This is a 100 Mbit Receiver. I will test with the hold-queue as i am at home.

Some more information:

1. CEF is on , IGMP v3 in use

2. In about 1 hour ~ 3-4 hang ups for each 1-3 seconds - apart from that everythings seems fine .

3, No high CPU - but if i am enter sh run i can see the screen from tv hangs for milliseconds. And that is reproducible.

4. CPU history over 72 hours 3 peaks in max 60 % normal 20 % in average.

I am not sure if that is a hardware issue or software . I will do a capture soon to see what in net is going up.. perhaps you have any ideas to test or debug some things before.

Thanks a lot

Regards

[Philip D'Ath]

The Cisco 2821 is an older router.  It is also possible that if the packet size is small, that it may simply be running out of capacity.

[cyberurmel]

Hi,

i know that is not the newest but which capacity you mean?? And how i can recheck /verify that?

As per Routing it should easily handle 85Mbit in Routing and my Wan Connection is 50 Mbit.. and Multicast packets are not use the whole bandwith too.

CPU is not more than 20 % in average...

[Philip D'Ath]

With small packets a 2821 can only do about 50Mb/s.

Can you post the first line from "show process cpu".  I want to see what the time spent servicing interrupts is.

[cyberurmel]

Hello Philip,

thanks for taking your time.

Output as attachment as TV and Internet are in use.

and i have already the settings for the scheduler like you suggest.

Regards

[Philip D'Ath]

Those settings look fine. You are not running out of router capacity.

Has using those scheduler settings either reduced or resolved the issue?

[cyberurmel]

No i had already these settings before and  it changed nothing due to the issue.

Today i will check without my L2/L3 Switch in between means directly with a non managed switches only the router uplink and the receiver.

If that nothing changes than i can solve out that device too and make a port mirroring with capture packeting.

[cyberurmel]

First check done..

If i only connect a simply switch between tv and router and also e.g. the wireless AP ... i have NO more stoppings since round about one hour!  But also have some artefacts by the command sh run on the router.  Reproducable.

But i would be fine with it if it will works such like now with my SG 300 switch.

Thats next question.. What is the difference and how to check / see???

[cyberurmel]

also added sh proc cpu sorted

:

#sh proc cpu sorted
CPU utilization for five seconds: 21%/8%; one minute: 21%; five minutes: 21%
 PID Runtime(ms)     Invoked      uSecs   5Sec   1Min   5Min TTY Process
 140    40911152   226604497        180 10.87% 10.96% 10.97%   0 IP Input

[Philip D'Ath]

Actually we may be able to solve this by adjusting the scheduler. Try this:

scheduler allocate 20000 1000