About three or four months ago, we’ve rolled out VoIP to our first remote site and was tasked to implement QoS. At the time, I knew a little about QoS (I still do) and that was the first reason why I had to read the QoS book last year. That […]

QoS Classification and Marking

Cisco’s recommendation is to leave the shaping values (Bc – committed burst and Tc – committed rate interval time) alone if you’re not servicing delay sensitive application, like voice. By default Class Based Shaping use 8000 bits for Bc and 125 ms for Tc if it is below 320 Kbps […]

Manipulating Shaping Values

QoS Layer 2 Marking Ethernet 802.1Q/p Switch (config-if)# mls qos 5 ! Sets 802.1Q CoS to 5 on outer frame Switch (config-if)# mls qos cos override ! Overrides any existing CoS value on the outer frame Frame Relay Discard Eligible Bit With Frame Relay, it uses 0 or 1 to […]

QoS Marking

QoS requirements and recommendations for data traffic: Best Effort Traffic should be marked to DSCP 0. Adequate bandwidth should be assigned to this class because majority of applications default to this class. Recommended is to set aside 25 percent for this class. Bulk Traffic should be marked to DSCP AF11; […]

QoS Requirements of Data and Control Plane

Key QoS requirements and recommendations for interactive video (video conferencing) traffic: Interactive video traffic should be marked to DSCP AF41; excess video conferencing traffic can be marked down by a policer AF42 or AF43. Loss should be no more than 1 percent. One way latency should be no more than […]

QoS Requirements for Video