external call quality issue

[michaelzhq]

Just done a new deployment with CUCM 7.1(5), 2921 H323 gateway and T1 PRI line. The overall call quality is good. However, we received few complaints about external calls recently. When both people speak at same time, it cuts audio out to both ends, like half-duplex communication. It can be reproduced with a certian number.

We monitor the call QoS statistic data during the call as follows:

Rcvr Codec:  G.711u

Sender Codec: G.711u

Rcvr Size: 20ms

Sender Size: 20ms

Rcvr Packets: ~3000

Sender Packets: ~3000

Avg Jitter: 1

Max Jitter: 32

Rcvr Discarded: 1

Rcvr Lost Packets: 0

MOS LQK:  4.5

Avg MOS LQK: 4.477

Min MOS LQK: 4.38

Max MOS LQK: 4.5

MOS LQK Version: .95

Cumulative Conceal Ratio: .0007

Interval Conceal Ratio:0

Max Conceal Ratio: 0.0199

Conceal Secs: 5

Severely Conceal Secs:0

Latency:0

Network Protocol: IPv4

I don't see problem with the data above.

Anybody has the similar experience? Where can I start the troubleshooting?

Thanks.

Michael

[Roman Rodichev]

Does this happen only when using speakerphone? I've see this before where a newer phone firmware resolves it. Although you are on 7.1(5) which is pretty new already.

[toormehdi]

Hi Michael,

Were you able to resolve this problem. We experiencing the same condition with v7.1(5)

In any input is much appreciated.

Thanks.

[michaelzhq]

It was partly resolved by IOS and phone load upgrades.

Are you using PRI line? If so, make sure it's error free.

Can you please post your IOS version, DSP version and phone load version?

Michael

[toormehdi]

Thanks Michael.

1. Series 2901 - Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.0(1)M1, RELEASE SOFTWARE (fc1)

2. Its PRI with MGCP - Both of the two Controllers appear error free.

3. DSPware version: 26.3.4

4. Phone load SCCP42.9-0-3S

5. The problem exists only on external calls.

T1 0/0/0 is up.
  Applique type is Channelized T1
  Cablelength is long 0db
  No alarms detected.
  alarm-trigger is not set
  Soaking time: 3, Clearance time: 10
  AIS State:Clear  LOS State:Clear  LOF State:Clear
  Version info Firmware: 20090408, FPGA: 13, spm_count = 0
  Framing is ESF, Line Code is B8ZS, Clock Source is Line.
  CRC Threshold is 320. Reported from firmware  is 320.
  Data in current interval (412 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Total Data (last 24 hours)
     0 Line Code Violations, 0 Path Code Violations,
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
T1 0/0/1 is up.
  Applique type is Channelized T1
  Cablelength is long 0db
  No alarms detected.
  alarm-trigger is not set
  Soaking time: 3, Clearance time: 10
  AIS State:Clear  LOS State:Clear  LOF State:Clear
  Version info Firmware: 20090408, FPGA: 13, spm_count = 0
  Framing is ESF, Line Code is B8ZS, Clock Source is Line.
  CRC Threshold is 320. Reported from firmware  is 320.
  Data in current interval (414 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Total Data (last 24 hours)
     0 Line Code Violations, 0 Path Code Violations,
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

[michaelzhq]

You have the exact same versions as we had before the upgrade.

We had a TAC case for this, based on the TAC's suggestion -- upgrade the IOS to 15.0(1)M4 or later (DSP will be upgraded with IOS), upgrade the phone load to 9-1-1.

Hope this helps.

[toormehdi]

Thanks Michael. We will upgrade the firmware and IOS.