SLA Metrics: One-way delay
The time between reception of an IP packet at an ingress POP and its transmission at an egress POP
Comprised of four components:
Propagation delay: ~5ms/1000km for fibre
Switching / processing delay: typically 10-20µs per packet
Scheduling / queuing delay
Serialisation delay: dependent upon line rate: 6ms for 1500 byte packet at 2Mbps, 80µs at STM-1, 1.25µs at STM-64
VoIP target one-way delay bound of 150ms (G.114)
RTT target of 250ms is common for interactive business data applications