I am having problems with VoIP over MLPPP over FrameRelay, and hopefully someone can explain any bugs? or things I've misunderstood as I explain, or major problems in the config... The end aim is to use this with ATM+Serial routers.
Two Cisco 2600's back to back, with Frame-Relay (Two DSU's crossed) running on Serial WIC's
Smartbits to inject simulated voice (64 byte UDP packets) and simulated data (1514 TCP packets).
On one occassions smartbits reported that the voice packets were transmitted with a 10ms window. The next day (and a week later), I can't acheive that result again... That's where the problem is (I need the simulated voice to go end-to-end in 10ms).
- Using the command sh policy-map interface virtual-access2, I can see that the class-map correctly matches the simulated data and simulated voice into the correct class (they are fed in via different interfaces).
- Using IOS 12.2(5) on the routers, however I read somewhere that with MLPPP that percentage rather than absolute values must be used in the policy-map. That doesn't seem to work with 12.2(5) - anyone else find this? tried also 12.2(8)T1 which allows the percentage command to be configured.
- I'm guessing that hte ppp multilink interleave/ppp multilink fragment-delay commands give priority to the PRIORITY queue... or do those command look for voice (in which case my simulated voice might be to blame)?
- config below
A week of going around in circles and havn't worked it out, so hoping someone else has the answer!
Regards,
Lee
class-map match-all ONE
matched by input interface (e0/0 from VOICE simulator)
class-map match-all TWO
matched by input interface (e0/1 from DATA simulator)
policy-map QoS-Policy
class TWO
bandwidth 8 ' also tried bandwidth percent 12
class ONE
priority 30 ' also tried priority percent 50
class class-default
fair-queue
interface Serial0/0.6 point-to-point
frame-relay interface-dlci 111 ppp Virtual-Template7
class VoIP
interface Virtual-Template7
bandwidth 64
ip address 172.20.7.2 255.255.255.0
service-policy output QoS-Policy
ppp authentication chap
ppp chap hostname host1
ppp chap password 7 00141215174C04140B
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave
!
map-class frame-relay VoIP
no frame-relay adaptive-shaping
frame-relay cir 64000
frame-relay bc 12000
frame-relay be 12000
frame-relay mincir 64000
