I want to check whether my WAN provider commits to 768 kbps of aggregated real time traffic (DSCP = EF)
I started 5 (five) IP SLA UDP JITTER operations on my router, each one sending 180 bytes packets paced at 10 milliseconds each. So 5*180= 900 bytes, times 100 packets per second should give me 90,000 bytes per second or 720 kbps.
To my surprise, the service provider observes that the rate of my packets is well above the rate I expected: 958 kbps:
"30 second offered rate 958000 bps"
This is a copy of one of the five operations I started on my router:
ip sla monitor 4000
type jitter dest-ipaddr 220.127.116.11 dest-port 24000 num-packets 27000 interval 10
My calculation for a 180 bytes packet was based on the sum of "request-data-size" (152 bytes), 8 bytes of UDP header and 20 bytes of IP header.
Â¿Am I missing anything else?
Any help will be greatly appreciated.
I see, traffic is measured on ATM.
A 180 bytes packet in AAL5/snap takes 5 cells, that is 5 x 48 bytes * 8 * 500 = 960 Kbps, virtually perfect match.
Note on the PVC you're actually transmitting at 1,060 Kbps including the 5 bytes per cell overhead.
If you're curious about protocol overhead: