PTP670 LINK - 88km - Link Capacity vs Aggregate Data Rate


Can someone explain the following:

Why is the link capacity not equal to the aggregate data rate attained by the PTP670 link.

Radio configuration:

1_ Antenna = 34dBi Dual-Pol (Radiowaves Standard Performance)

Attached actual link status and relative spectrum status.

Hi Gerry,

This a great long-distance link at 88 km!

Normally, Aggregate Data Rate is equal to Link Capacity. The only time this is not the case is when Link Symmetry is configured as Adaptive. In this case, the TDD burst duration in each direction depends on the utilization of the link. When one direction of the link is fully utilized, Master ODU inreases the burst duration for that direction. If a direction is not fully utilized, the Master ODU reduces the burst duration. This optimizes in two ways: First, it reduces latency if the link is lightly loaded and increases capacity if it is heavily loaded (sacrificing latency to do so). Second, it distribuites capacity between the to directions to address asymmetric traffic loads.

The Link Capacity control shows the capacity you would achieve with heavy symmetric loading. The Aggregate Data Rate control shows the capacity you have under the current loading. Normally, there can be a small difference in Adaptive symmetry. In your link, the long range means that the difference is more noticeable.

Does this help?


Thanks Mark for the explanation.

Will it be better to set link symmetry to 1:1 ratio. This is a last mile access for a MPLS network.