QoS | Types of Delay

- Processing delay: time it takes for a router to take the packet from an input interface, examine it & put it into the output queue of the output interface (depends cpu speed/utilization, ip switching mode, router architecture, configured feature on both in/out interface)
- Queuing delay: time a packets resides in the output queue of a router (depens on number of & size of packets already in queue, bw of int, queue mechanism)
- Serialization delay: time it takes to place the 'bit on the wire' (physical medium for transport)
- Propagation delay: time it takes to transmit a packet (depends on the type of media interface)

Ways to reduce delay: upgrade bandwidth, forward important packets first, compress payload of layer 2 frame, compress ip packet headers