Packet Content

Packet Size

The length distribution of the packets transmitted for a stream. The length of the packets transmitted for a stream can be varied from packet to packet, according to a choice of distributions within a specified min…max range. The length of each packet is reflected in the size of the payload portion of the packet, whereas the header has constant length. Length variation complements, and is independent of, the content variation produced by header modifiers.

Corresponding low-level API class: PS_PACKETLENGTH

# Packet Size
await stream.packet.length.set(length_type=enums.LengthType.FIXED, min_val=64, max_val=64)
await stream.packet.length.set(length_type=enums.LengthType.INCREMENTING, min_val=64, max_val=1500)
await stream.packet.length.set(length_type=enums.LengthType.BUTTERFLY, min_val=64, max_val=1500)
await stream.packet.length.set(length_type=enums.LengthType.RANDOM, min_val=64, max_val=1500)
await stream.packet.length.set(length_type=enums.LengthType.MIX, min_val=64, max_val=64)

resp = await stream.packet.length.get()
resp.length_type
resp.min_val
resp.max_val

Packet Auto Size

Executing PS_AUTOADJUST will adjust the packet length distribution (PS_PACKETLENGTH) of the stream:

  1. Set the type of packet length distribution (PS_PACKETLENGTH <length_type>) to FIXED.

(2) Set the lower limit on the packet length (PS_PACKETLENGTH <min_val>) to exactly fit the specified protocol headers, TPLD and FCS (but never set to less than 64).

  1. Set the payload type of packets transmitted for the stream (PS_PAYLOAD <payload_type>) to PATTERN.

(4) If necessary, also set the maximum number of header content bytes (P_MAXHEADERLENGTH <p_maxheaderlength_label> <max_header_length>) that can be freely specified for each generated stream of the port to a higher value, if needed to accommodate the header size of the stream (implicitly given by the PS_PACKETHEADER command).

(5) If the needed maximum header length (P_MAXHEADERLENGTH <p_maxheaderlength_label> <max_header_length>) is not possible with the actual number of active streams for the port, the command will fail with: <BADVALUE>.

Corresponding low-level API class: PS_AUTOADJUST

# Packet Auto Size
await stream.packet.auto_adjust.set()

Payload Type

The payload content of the packets transmitted for a stream. The payload portion of a packet starts after the header and continues up until the test payload or the frame checksum. The payload may vary in length and is filled with either an incrementing sequence of byte values or a repeated multi-byte pattern. Length variation complements and is independent of the content variation produced by header modifiers.

Corresponding low-level API class: PS_PAYLOAD

# Payload Type
# Pattern string in hex, min = 1 byte, max = 18 bytes
await stream.payload.content.set(payload_type=enums.PayloadType.PATTERN, hex_data=Hex("000102030405060708090A0B0C0D0E0FDEAD"))
await stream.payload.content.set(payload_type=enums.PayloadType.PATTERN, hex_data=Hex("F5"))

# Patter string ignored for non-pattern types
await stream.payload.content.set(payload_type=enums.PayloadType.INC16, hex_data=Hex("F5"))
await stream.payload.content.set_inc_word("00")
await stream.payload.content.set(payload_type=enums.PayloadType.INC8, hex_data=Hex("F5"))
await stream.payload.content.set_inc_byte("00")
await stream.payload.content.set(payload_type=enums.PayloadType.DEC8, hex_data=Hex("F5"))
await stream.payload.content.set_dec_byte("00")
await stream.payload.content.set(payload_type=enums.PayloadType.DEC16, hex_data=Hex("F5"))
await stream.payload.content.set_dec_word("00")
await stream.payload.content.set(payload_type=enums.PayloadType.PRBS, hex_data=Hex("F5"))
await stream.payload.content.set_prbs("00")
await stream.payload.content.set(payload_type=enums.PayloadType.RANDOM, hex_data=Hex("F5"))
await stream.payload.content.set_random("00")

resp = await stream.payload.content.get()
resp.hex_data
resp.payload_type

Extended Payload

This command controls the extended payload feature. The PS_PAYLOAD command described above only allow the user to specify an 18-byte pattern (when PS_PAYLOAD is set to PATTERN). The PS_EXTPAYLOAD command allow the definition of a much larger (up to MTU) payload buffer for each stream. The extended payload will be inserted immediately after the end of the protocol segment area. The feature requires the P_PAYLOADMODE command on the parent port being set to EXTPL. This enables the feature for all streams on this port.

Note

Use await port.payload_mode.set_extpl() to set the port’s payload mode to Extended Payload.

Corresponding low-level API class: PS_EXTPAYLOAD

# Extended Payload
# Use await port.payload_mode.set_extpl() to set the port's payload mode to Extended Payload.
await stream.payload.extended.set(hex_data=Hex("00110022FF"))

resp = await stream.payload.extended.get()
resp.hex_data