Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?




Hierarchy Level


Enable the Two-Way Active Measurement Protocol (TWAMP) server for managed control on the TCP port that reflects the test packets.


client-limit limit

Specify the maximum number of TWAMP clients.

  • Range: 0 to 1000

  • Default: 0 (disabled, which means there is no limit to the number of clients)

client-list list-name { address address <routing-instance [instance-name...]>}

Specify a list of clients and their corresponding addresses and routing instances. If you do not specify a routing instance, the default routing table is used (inet.0).

  • Syntax: address address <routing-instance [instance-name...]>—Specify one address statement for each client, configuring an IPv4 address and, optionally, a list of routing instances for each one, to filter packets accordingly.

control-inactivity-timeout seconds

Specify the number of seconds to wait after the control connection becomes inactive before timing out.

  • Range: 0 through 86400 seconds; specify 0 to disable.

  • Default: 900 seconds

control-maximum-duration seconds

Specify how long the control connection remains up.

  • Range: 0 through 86400 seconds

  • Default: 0 (disabled, which means there is no limit to the length of time the control connection remains up)

control-per-client-limit number

Specify the maximum number of control connections allowed per client.

  • Range: 0 to 1000

  • Default: 0 (disabled, which means there is no limit to the number of control connections allowed)

offload-type (none | inline-timestamp | pfe-timestamp)

Enable timestamping of TWAMP probe messages in the Routing Engine, inline in the hardware, or Packet Forwarding Engine host processor. Prior to Junos OS Evolved 22.3R1, for IPv6 traffic, you must configure none, as only Routing Engine timestamping is supported. Starting in Junos OS Evolved 22.3R1, you can configure the pfe-timestamping option for IPv6 traffic.

  • none—Timestamping in the Routing Engine.

  • inline-timestamping—Timestamping inline, in the hardware at the generator, and reflection in the hardware at the reflector. When this option is configured for an ACX router, the ACX can act as either a server or client, but not both. Also for an ACX router, inline-timestamping is not supported on PM50 ports if FEC74 is enabled on that port. You can configure the inline-timestamping option for up to 256 test sessions.

  • pfe-timestamping—Timestamping in the Packet Forwarding Engine.

  • Default: pfe-timestamp

port number

Specify which port can accept TWAMP control connections.

  • Range: You can specify port 862, or any port from 49152 through 65535.

  • Default: 862 (IANA port for TWAMP)


Configure stateful sequencing to generate the sequence number in the reflected payload independently, instead of copying the sequence number from the client frame. With independently generated sequence numbers, the software is able to detect in which direction drops have occurred. Unidirectional drop values are inferred minimum values, and are not guaranteed to be exact. The software relies on an actual packet to be reflected successfully to be able to compute differences. If such a packet does not occur, then the software is unable to tell whether the drop happened in the egress or ingress direction.

test-per-client-limit limit

Specify the maximum number of test sessions allowed per client.

  • Range: 0 to 1000

  • Default: 0 (disabled, which means there is no limit to the number of test sessions allowed per client)

Required Privilege Level

system—To view this statement in the configuration.

system-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Evolved 20.3R1.

offload-type and stateful-sequence options introduced in Junos OS Evolved Release 23.4R1.