I was looking for a recommendation on max-reserved-bandwidth & qos-map
I am looking for the maximize a voice only on 900e 3rd gen. Is there a recommend max-reserved-bandwidth? Up to 90%??
THIS WAS DONE WITH THE MAX-RESERVED-BANDWIDTH at default, 75%
The balance of kbps works out exactly.
qos map VOICE 10
match dscp 46
match dscp cs3
match dscp 41
priority percent 70
exit
!
qos map VOICE 20
match dscp cs2
bandwidth percent 5
exit
!
interface ppp 1
qos-policy out VOICE
AT PPP 1 INT MAX MAX-RESERVED-BANDWIDTH 85%
qos map VOICE 10
match dscp 46
match dscp cs3
match dscp 41
priority percent 80
qos map VOICE 20
match dscp cs2
bandwidth percent 5
interface ppp 1
description ppp 1
ip address xxxxxxxxxxxxxxxxxx
media-gateway ip primary
peer default ip address xxxxxxxxxxxxx
max-reserved-bandwidth 85
qos-policy out VOICE
no shutdown
cross-connect 1 t1 0/1 1 ppp 1
It's at 75% because that's a good compromise. You can go higher but if everything is voice and you're doing no data at all do you really need QoS? The idea of limiting it is to allow routing protocols, administrative access, etc. in the event of severe congestion. If you're using 75% of the pipe for priority traffic, you probably need a bigger pipe or will very soon.
Yes, you can go to 90%. Keep the RTP in a low-latency priority queue. SIP needs little bandwidth and can take buffering and latency but avoid drops with reserved bandwidth. I've run SIP at 2% on busy networks. Make sure your DSCP values are being set as intended and reset to 0 any DSCP from untrusted networks.