This article discusses the maximum output speed of a 10-Gigabit Ethernet interface that works in WAN PHY framing mode, which is 9.29419 GB. This can be verified with the command, ‘show interfaces queue xe-*/*/*’ :
‘show interfaces queue xe-*/*/*’
user@router> show interfaces queue xe-4/0/1 Physical interface: xe-4/0/1, Enabled, Physical link is Up Interface index: 217, SNMP ifIndex: 567 Description: 10G-interface Forwarding classes: 16 supported, 4 in use Egress queues: 8 supported, 4 in use Queued: Packets : 10883810103117 1036845 pps Bytes : 10118080209471924 9240575728 bps <---maximum output speed of interface xe-4/0/1 Transmitted : Packets : 10883809107131 1036845 pps Bytes : 10118079086705450 9240575728 bps Tail-dropped packets : 21361 0 pps RED-dropped packets : 974625 0 pps Low : 949240 0 pps Medium-low : 0 0 pps Medium-high : 0 0 pps High : 25385 0 pps RED-dropped bytes : 1099272800 0 bps Low : 1068329480 0 bps Medium-low : 0 0 bps Medium-high : 0 0 bps High : 30943320 0 bps ......
The maximum output speed of a10-Gigabit Ethernet interface that works in the WAN PHY framing mode is 9.29419 Gbit/s. This is by design.
For a 10-Gigabit Ethernet interface to work in the WAN PHY Framing mode, it must be compatible with SONET OC-192/SDH VC4-64C.
The clock rate of SONET OC-192/SDH VC4-64C is 9.95328 Gbit/s, as per IEEE802.3ae, the SONET cost is 1/27. Hence, the valid payload is 26/27 and the result is 9.95328 Gbit/s * 26/27 = 9.58464 Gbit/s.
Also, as per IEEE802.3ae, the coding type of mbnb is 64b/66b. This function is achieved by the Physical Coding Sublayer (PCS) layer. Hence, the final valid payload is 64/66 and the result is 9.58464 Gbit/s * 64/66 = 9.29419 Gbit/s.