Just wanted to ask for advice regarding the the following problem. I have a T1 line for data to AT&T. The interface is up and and line is up. However, I am getting intermitten ridiculous ping times to my 1st hop AT&T gateway. It's causing my VPN users to get extremely bad voice quality (Cisco IP communicator). I originally had service policy QoS applied for voice on the outgoing serial interface. However, with the slow ping times, I removed it just in case it was affecting performance. Even with no policy outgoing or incoming on the serial interface, I am still getting bad ping times. Here's the sh interface for the serial interface:
Serial0/0/1:0 is up, line protocol is up
Hardware is GT96K Serial
Internet address is 12.X.X.X/X
MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
reliability 255/255, txload 20/255, rxload 139/255
Encapsulation PPP, LCP Open
Open: IPCP, loopback not set
Keepalive set (10 sec)
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 6d15h
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 21
Queueing strategy: weighted fair
Output queue: 0/1000/64/21 (size/max total/threshold/drops)
Conversations 0/9/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 1152 kilobits/sec
5 minute input rate 839000 bits/sec, 103 packets/sec
5 minute output rate 122000 bits/sec, 74 packets/sec
17747759 packets input, 694178341 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
40 input errors, 40 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
12549691 packets output, 2116392419 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 output buffer failures, 0 output buffers swapped out
1 carrier transitions
Timeslot(s) Used:1-24, SCC: 1, Transmitter delay is 0 flags
ANy help is appreciated.
I would think with the difference in speed between the T1 and Ethernet, and the fact that you have 70% for voice, it is highly unlikely that the Ethernet QoS has anything to do with it. I assume the voice gets a priority queue anyway on that side.
There is not much you can do with ingress QoS. The QoS needs to be applied at the other end of the link. You could ask AT&T if they would be willing to do that for you, but I bet they would prefer to sell you a second line. You aould also ask them for drop statistics from their end.
I suppose you could install some WRED so you slow down any TCP sessions when the loading gets high. As I said, ping is not a very good metric for judging this, but voice quality is.
But all in all, it looks like you are trying to squeeze a quart into a pint pot.