You don't want to use wieghted fair queueing becase voice priority will be non existent when the link becomes congested.
You can use low lantency queueing to mark and provide a low latency queue for high priority traffic over frame-relay.
On the LAN side it is important to provide a queueing mechanism in your core and access switches so that voice traffic is queued out LAN interfaces to your 2600 first.
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There are 2 portions
RTP or constant voice traffic and Call control traffic wich does call setup and tear down. usually RTP is set up with an IP Precedence of 5 and Call Control has a precedence of 3. Only 8k of bandwidth is needed for call control traffic for hundreds of phones but depending on how many phones you have you can limit the priority or bandwidth in the policy.
!
!
!
map-class frame-relay voice
frame-relay cir 512000
frame-relay mincir 512000
service-policy output QOS-Policy
!
!
int serial0
Frame-relay traffic-shaping
!
int serial0/0.100
frame-relay class voice
!
!
!
class-map VoIP-RTP
match access-group 102
class-map VoIP-Control
match access-group 101
!
policy-map QOS-Policy
class VoIP-RTP
priority percent 100
class VoIP-Control
bandwidth 8
class class-default
fair-queue
!
access-list 102 permit udp any any range 16384 32767
access-list 102 permit ip any any precedence 5
access-list 102 permit ip any any dscp ef
!
access-list 101 permit tcp any any range 2000 2002
access-list 101 permit tcp any any eq 1720
access-list 101 permit tcp any any range 11000 11999
access-list 101 permit udp any any eq 2427
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This puts ip precedence 5 and 3 in different queues on my switch.
For my 6500
#qos
set qos enable
set qos map 2q2t tx 2 1 cos 3
set qos map 1p2q2t tx 2 1 cos 3
set qos wred 1p2q2t tx queue 1 40:80 70:100
set qos wred 1p2q2t tx queue 2 40:80 70:100
set qos cos-dscp-map 0 8 16 26 32 46 48 56
set qos ipprec-dscp-map 0 8 16 26 32 46 48 56
