Explanation

The scheduling mode for outgoing traffic from the port, specifying how multiple logical streams are merged onto one physical port. There are four primary modes:

Normal Interleaved: The streams are treated independently, and are merged into a combined traffic pattern for the port, which honors each stream’s ideal packet placements as well as possible. This is the default mode.

Strict Uniform: This is a slight variation of normal interleaved scheduling, which emphasizes strict uniformity of the inter-packet-gaps as more important than hitting the stream rates absolutely precisely.

Sequential: Each stream in turn contribute one or more packets, before continuing to the next stream, in a cyclical pattern. The count of packets for each stream is obtained from the PS_PACKETLIMIT parameter value for the stream. The individual rates for each stream are ignored, and instead the overall rate is determined at the port-level using the P_RATExxx parameters. This in turn determines the rates for each stream, taking into account their packet lengths and counts. The maximum number of packets in a cycle (i.e. the sum of PS_PACKETLIMIT for all enabled streams) is 500. If the packet number is larger than 500, will be returned when attempting to start the traffic (P_TRAFFIC ON).

Burst*: When this mode is selected, frames from the streams on a port are sent as bursts as depicted below:

The Burst Period is defined in the P_TXBURSTPERIOD parameter. For the individual streams the number of packets in a burst is defined by the PS_BURST parameter, while the Inter Packet Gap and the Inter Burst Gap are defined by the PS_BURSTGAP parameter.

Summary

set and get, value type: B

Parameters

txmode: coded byte, containing the loop-back mode for the port:

• NORMAL (interleaved packet scheduling)
• STRICTUNIFORM (strict uniform mode)
• SEQUENTIAL (sequential packet scheduling)
• BURST (burst mode)

Example, set or get:

0/5 P_TXMODE NORMAL

Explanation

The port-level rate of the traffic transmitted for a port in sequential tx mode, expressed in millionths of the effective rate for the port. The bandwidth consumption includes the inter-frame gaps, and does not depend on the length of the packets for the streams.

Summary

set and get, value type: I

Parameters

fraction: integer, port rate expressed as a value between 0..1000000.

Example, set or get:

0/1 P_RATEFRACTION 500000

Explanation

The port-level rate of the traffic transmitted for a port in sequential tx mode, expressed in packets per second. The bandwidth consumption is heavily dependent on the length of the packets generated for the streams, and also on the inter-frame gap for the port.

Summary

set and get, value type: I

Parameters

pps: integer, port rate expressed as packets per second.

Example, set or get:

0/1 P_RATEPPS 300000

Explanation

The port-level rate of the traffic transmitted for a port in sequential tx mode, expressed in units of bits per-second at layer-2, thus including the Ethernet header but excluding the inter-frame gap. The bandwidth consumption is somewhat dependent on the length of the packets generated for the stream, and also on the inter-frame gap for the port.

Summary

set and get, value type: L

Parameters

bps: long integer, port rate expressed as bits-per-second.

Example, set or get:

0/1 P_RATEL2BPS 800000000

Explanation

For a port in sequential tx mode, query the port-level rate of the traffic transmitted in the manner it was last expressed. The response is one of P_RATEFRACTION, P_RATEPPS, or P_RATEL2BPS.

Summary

get only.

Parameters

None

Example, get:

0/1 P_RATE ?

Explanation

In Burst tx mode this parameter defines the time from start of one sequence of bursts (from a number of streams) to the start of next sequence of bursts. NB: Only used when Port TX Mode is ”Burst”.

Summary

set and get, value type: I 

Parameters

period: integer, burst period expressed in micro-seconds. 

Example, get:

0/1 P_TXBURSTPERIOD 300000