Vyatta NOS documentation

Learn how to install, configure, and operate Vyatta Network Operating System (Vyatta NOS), which helps to drive our virtual networking and physical platforms portfolio.

service path-monitor policy <name> requires type twping

Controls the definition of a TWAMP-based policy for a path monitor.

The policy attributes (constraints) are similar to those for a ping policy: latency (delay), jitter, and packet loss.

Unlike ping policies, the TWAMP protocol supports separate metrics for the send and reflect (receive) paths in addition to the round trip.

Note: The policy type twping must match the type of the parent monitor object.

This command supports a matrix of parameters for round trip and individual directions (defined in the Syntax table):

  • Send (transmit): delay and jitter
  • Reflect (receive): delay and jitter
  • Round trip: delay, jitter, packet loss
Some parameter combinations have two keywords preceding the variable, for example:
  • ... jitter threshold <ms>, ... jitter robustness <ms>
  • ... time threshold <ms>, ... time tolerance <ms>

The Syntax table is divided by direction of packet flow (after your policy name specification). If you configure every optional and mandatory parameter, the total of entries of this command is 21 (in the current release). For example:

  • set service path-monitor policy <name> requires type twping reflect jitter ...
  • set service path-monitor policy <name> requires type twping reflect time robustness <r-count> ...
  • set service path-monitor policy <name> requires type twping round-trip jitter ...
  • set service path-monitor policy <name> requires type twping round-trip loss ...
  • set service path-monitor policy <name> requires type twping round-trip time robustness <r-count> ...
  • set service path-monitor policy <name> requires type twping send jitter ...
  • set service path-monitor policy <name> requires type twping send time robustness <r-count> ...
Table 1.
ParameterDescriptionMetric values
policy <name>The alphanumeric name of the policy object.(user-defined)
reflect

After the time or jitter keyword, one of the following keywords also follows it. The metric values can apply to any reflect variable.

  • threshold (maximum delay)
  • tolerance
  • robustness (r-count)

Robustness is the number of consecutive samples that a Path Monitor must collect before it indicates a policy change (into or out of compliance).

threshold (mandatory):

  • Range: 1 to 5000 ms

tolerance (optional):

  • Range: 0 to 1000 ms
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1

The jitter parameter is the maximum variation in packet latency.

The robustness parameter controls the number of consecutive samples that a path monitor must collect before it indicates a policy change (into or out of compliance).

threshold (mandatory):

  • Range: 1 to 1000 ms

tolerance (optional):

  • Range: 0 to 1000 ms
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1
send

After the time or jitter keyword, one of the following keywords also follows it. The metric values can apply to any send variable.

  • threshold (maximum delay)
  • tolerance
  • robustness (r-count)

The robustness parameter controls the number of consecutive samples that a path monitor must collect before it indicates a policy change (into or out of compliance).

threshold (mandatory):

  • Range: 1 to 5000 ms

tolerance (optional):

  • Range: 0 to 1000 ms
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1

The jitter parameter is the maximum variation in packet latency for this direction.

  • threshold (maximum delay)
  • tolerance
  • robustness (r-count)

threshold (mandatory):

  • Range: 1 to 1000 ms

tolerance (optional):

  • Range: 0 to 1000 ms
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1
round-trip

After the time or jitter keyword, one of the following keywords also follows it. The metric values can apply to any round-trip variable.

  • threshold (maximum delay)
  • tolerance
  • robustness (r-count)

The robustness parameter controls the number of consecutive samples that a path monitor must collect before it indicates a policy change (into or out of compliance).

threshold (mandatory):

  • Range: 5 to 10000 ms

tolerance (optional):

  • Range: 0 to 1000 ms
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1

The jitter parameter is the maximum variation in packet latency for the entire round trip. Values can apply to any of these keywords.

  • threshold (maximum delay)
  • tolerance
  • robustness (r-count)

threshold (mandatory):

  • Range: 1 to 1000 ms

tolerance (optional):

  • Range: 0 to 1000 ms
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1

Optional loss is the amount of packets lost over the entire round trip, expressed as a percentage. robustness also is an optional value for loss.

Note: Combined threshold and tolerance must be less than 100, otherwise there will be a configuration error.

The robustness parameter controls the number of consecutive samples that a path monitor must collect before it indicates a policy change (into or out of compliance).

threshold (optional):

  • Range: 0 to 75 %
  • 25 %

tolerance (optional):

  • Range: 0 to 50 %
  • Default: 5 ms

r-count (optional):

  • Range: 1 to 10
  • Default: 1