Hello and thanks for taking a look,
I am trying to achieve the following behavior through Cisco QoS.
The goal is that when rtp audio packets are flowing then VoIP Queue reserves 464kbps and the other queues have 64 kbps available to share.
Therefore, if I have an uplink of 512kbps and If there are rtp packets going through the interface, I want the Policy class to reserve 464kbps (regardless of how many actual kbps of rtp audio packets are flowing through). If there are no rtp audio packets going through the interface then share the the 512kbps according to the other classes.
Another way to look at what I am trying to achieve is the following (maybe it will help to clarify):
If RTP Packets in class CCP-Voice-1 are present then shape all other traffic to 64kbps
This is my current config:
class-map match-any CCP-Transactional-1
>> Therefore, if I have an uplink of 512kbps and If there are rtp packets going through the interface, I want the Policy class to reserve 464kbps (regardless of how many actual kbps of rtp audio packets are flowing through). If there are no rtp audio packets going through the interface then share the the 512kbps according to the other classes.
Class Based Weighted Fair Queueing has built in elasticity and resources unused by VOIP packets are available for other resources.
This is usually enough.
2) about your configuration
there are some strange commands on WAN interface Fas4:
if you set bandwidth to 512 kbps the max-reserved-bandwidth should be set to 100 (100%) and not to 1.
The bandwidth command sets a new reference value for QoS.
ip mtu 576: this MTU is too small and it causes a lot of fragmentation of data traffic IP packets
I usually mark on LAN interfaces and then match on DSCP or IP precedence settings on exit interface this helps in troubleshooting as the command show policy-map interface provides counters for each traffic class and so you can compare traffic entering the router with traffic that is sent out the WAN interface.
Hope to help
You are correct I did notice I had 1% and not 100%, I fixed this soon after my post. Still it did not fix my issue.
I have set MTU to 576 bytes and MSS to 536 bytes for the following reason:
I was hoping I could implement Link Fragmentation and Interleaving; unfortunately soon I discovered this only works for PPP connections so my FastEthernet connected to my Cable Modem would not support it.
Is it possible to allow the elasticity of bandwidth only when there are no VoIP packets present?
My goal is to achieve this behavior using just the router (perhaps with EEM TCLs - if someone out there could code it):