The quality for internal, intersite calls over the WAN using G.729A codec is good (considering that G.729A is compressing the voice), indicating that the local WAN connection is not the issue. We also made traceroute and tests which show the overall connectivity to the IP telephony hub and H.323 trunk service provider is good.
However, the quality of G.729A calls over the public network (H.323 IP trunk to service provider) is bad for the direction coming from the service provider to the IP phone: the users on a 4610, 4621SW or 9620 complain of low level, robotic voice heard from external parties for both incoming and outgoing calls via the H.323 IP trunk. The external party is not complaining of bad quality.
We extracted the sound from a wireshark trace taken by mirroring the IP phone port: the sound from the trace is good. The sound recorded at the handset or headset of the Avaya phone however is bad. We made a spectrum analysis and saw that all the low sound frequencies below 2 kHz are cutoff and this explains the bad voice quality and low level because normally most of the voice sound is below 2 kHz.
Software/Firmware is:
- for 46xx: 2.9 SP 1 with patch 9.046a
- for 9620: 3.1.0
- ACM: 5.2.1
Does anyone know how we can solve this?
Thanks!
However, the quality of G.729A calls over the public network (H.323 IP trunk to service provider) is bad for the direction coming from the service provider to the IP phone: the users on a 4610, 4621SW or 9620 complain of low level, robotic voice heard from external parties for both incoming and outgoing calls via the H.323 IP trunk. The external party is not complaining of bad quality.
We extracted the sound from a wireshark trace taken by mirroring the IP phone port: the sound from the trace is good. The sound recorded at the handset or headset of the Avaya phone however is bad. We made a spectrum analysis and saw that all the low sound frequencies below 2 kHz are cutoff and this explains the bad voice quality and low level because normally most of the voice sound is below 2 kHz.
Software/Firmware is:
- for 46xx: 2.9 SP 1 with patch 9.046a
- for 9620: 3.1.0
- ACM: 5.2.1
Does anyone know how we can solve this?
Thanks!
