How have you classifed your Voice media, including the voice for your Video conferencing?
When you refer to the fact that you experience choppy voice, is this across all VoIP call or only your Video calls?
Is all voice media (rtp) routed across a specific leased line? Or is it seperated between the two lease lines, for example all video including the voice media is routed across one link, and all IP Phone voice media route across the other?
Which of these is affected by choppy voice?
If I read correctly between the lines, your problem is the voice across the Video conference? If this is the case then ensure that you have configure LLQ for your EF traffic, and this it not classified together with Video (AF41) in a single class.
Can you post the configuration of the gateway to identify how you have classifed your traffic.
Have you consider NBAR for protocol discovery when classifying traffic for your class-maps. This can ensure that you are classify the media correctly.
for example:-
class-map match-any VIDEO
match protocol rtsp
match ip dscp AF41
class-map match-any VOIP-RTP
match protocol rtp
match ip dscp EF
!
policy-map CBWFQ-QOS-2Mb
class VOIP-RTP
priority 160
class VIDEO-CONFERENCING
bandwidth 400
class class-default
fair-queue
!
!
policy-map Shape-QOS-2Mb
class class-default
shape average 2048000
service-policy CBWFQ-QOS-2Mb
!
Hope this helps.
Allan.