Automatic bandwidth allows to dynamically adjust bandwidth reservation based on the measured traffic. RSVP automatic bandwidth monitors the traffic rate on a Label Switched Path (LSP) and resizes the bandwidth to align it closely with the traffic in the tunnel. RSVP automatic bandwidth is configured on individual LSPs at every headend router.

Auto bandwidth can be added to an operational LSP at any time, but no bandwidth change occurs until a future trigger event or auto bandwidth profile configured with initial bandwidth or minimum bandwidth. Auto bandwidth may also be removed from an operational LSP at any time and this would re-signal the LSP with no bandwidth reservation.

The characteristics of the RSVP auto-bandwidth are:

In large MPLS transport networks in service provider settings with this capability:

Configure Layer 3 interfaces, like port channel interfaces (e.g., po1), and assign specific IP addresses for proper identification and routing. Additionally, assign loopback IP addresses to establish essential points of connectivity. These configurations establish the efficient network routing and communication.

Configure IGP for dynamic routing by following the steps mentioned. This setup includes enabling ISIS for dynamic routing and configuring OSPF for the network.

Enable Resource Reservation Protocol (RSVP) on all nodes to optimize traffic routing and quality of service. RSVP reserves network resources along specified paths to enhance network performance and reliability.

Establish a trunk is required on edge routers participating in label-switching using defined path. Configuring the RSVP path is optional.

Configure various nodes within the topology to set up a RSVP-Auto bypass tunnels.

The sample topology includes Edge Nodes (PE1 and PE2) and core Nodes (P1).

Primary path is defined via PE1-P1-PE2.

Verify auto bandwidth adjustments information as below:

 

Verify auto bandwidth on boot adjustments information as below:

The RSVP auto-bandwidth uses the following configuration commands.

Use this command to configure an auto bandwidth profile. The profile will have default settings if any parameter not configured explicitly. User can configure parameters to their need within auto bandwidth profile.

Use no parameter of this command to delete auto bandwidth profile.

None

Config mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure an auto-bandwidth profile:

The following example describes how to delete the auto bandwidth profile:

Use this command to configure a sample interval value in minutes on the auto bandwidth profile. Sample interval determines the frequency at which rate samples collected from associated trunks. Sample interval must not be configured more than adjust interval as no samples can be collected within an adjustment cycle in such case.

Use the no parameter to remove the sample interval configuration.

5 minutes

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure sample interval in the auto bandwidth profile:

The following example describes how to remove configured sample interval in the auto bandwidth profile:

Use this command to configure a adjust interval value in minutes on the auto bandwidth profile. Adjust interval determines the duration of the adjustment cycle. Bandwidth update decisions for active session of associated trunks are taken after every adjustment cycle. Adjust interval must not be configured less than sample interval as no samples can be collected within an adjustment cycle in such case.

Use the no parameter to remove the adjust interval configuration.

30 minutes

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure adjust interval in the auto bandwidth profile:

The following example describes how to remove configured adjust interval in the auto bandwidth profile:

Use this command to configure minimum bandwidth on the auto bandwidth profile. Even when traffic flow is much lesser than minimum bandwidth, LSP will be reserved with the configured minimum bandwidth during bandwidth adjustment process. When auto bandwidth profile associated with trunk, LSP will be signaled with minimum bandwidth when initial bandwidth is not configured in the profile.

Use the no parameter to remove the minimum bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure minimum bandwidth in a profile:

The following example describes how to remove the minimum bandwidth configuration from the profile:

Use this command to configure maximum bandwidth on the auto bandwidth profile. Even when traffic flow is much higher than maximum bandwidth, LSP will be reserved with the configured maximum bandwidth during bandwidth adjustment process. Operator notification is generated if the traffic rate samples collected are higher than the maximum bandwidth but the reservation is limited to maximum bandwidth.

Use the no parameter to remove the maximum bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure maximum bandwidth in a profile:

The following example describes how to remove the maximum bandwidth configuration from the profile:

Use this command to configure initial bandwidth on the auto bandwidth profile. When auto bandwidth profile associated with trunk, LSP will be signalled with initial bandwidth when initial bandwidth is configured in the profile. For trunks which are already associated with auto bandwidth profile and the system going through reload, initial bandwidth will not be applicable as on boot computation will trigger to update active sessions with bandwidth as per the on boot period traffic rate sample computation.

Use the no parameter to remove the initial bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure initial bandwidth in a profile:

The following example describes how to remove the initial bandwidth configuration from the profile:

Use this command to configure underflow threshold in percentage or absolute value format on the auto bandwidth profile. Underflow threshold sets the amount of reduction in traffic rate sample to detect an eligible underflow. As an example, absolute underflow threshold 10m when current bandwidth is 200m means, a traffic rate sample of 190.1m will not be considered eligible underflow sample and a sample of 189.9m will be considered eligible underflow sample.

When all the traffic rate samples collected for an auto bandwidth profile associated trunk cross underflow threshold in an adjustment cycle, then the highest eligible traffic rate sample will be considered to re-signal the session with new bandwidth at the end of an adjustment cycle.

Constraints like underflow-limit and underflow-threshold-activate-bandwidth will add additional logic on how bandwidth update action is taken. This will be discussed in respective sections.

If underflow threshold is not configured, then minor reduction in traffic rate sample also will be considered as eligible underflow bandwidth sample. So, underflow and overflow threshold is a recommended configuration even though it is not mandatory.

When underflow threshold is configured in percentage, the threshold will be computed based on the current bandwidth and the percentage value. Example, underflow threshold 10% for a current bandwidth of 100m means a sample of 90m or lesser will be considered eligible underflow sample. Underflow threshold can be configured either as absolute value or in percentage but not both.

Use the no parameter to remove the underflow bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure underflow bandwidth in percentage format in a profile:

The following example describes how to remove the underflow bandwidth configuration from the profile:

Use this command to configure overflow threshold in percentage or absolute value format on the auto bandwidth profile. Overflow threshold sets the amount of increase in traffic rate sample required to detect an eligible overflow. As an example, absolute overflow threshold 10m when current bandwidth is 200m means, a traffic rate sample of 209.9m will not be considered eligible overflow sample and a sample of 210.1m will be considered eligible overflow sample.

When a traffic rate sample collected for an auto bandwidth profile associated trunk crosses overflow threshold in an adjustment cycle, then the highest eligible traffic rate sample will be considered to re-signal the session with new bandwidth at the end of adjustment cycle.

Constraints like overflow-limit and overflow-threshold-activate-bandwidth will add additional logic on how bandwidth update action is taken. This will be discussed in respective sections.

If overflow threshold is not configured, then minor increase in traffic rate sample also will be considered as eligible overflow bandwidth sample. So, underflow and overflow threshold is a recommended configuration even though it is not mandatory.

When overflow threshold is configured in percentage, the threshold will be computed based on the current bandwidth and the percentage value. Example, overflow threshold 10% for a current bandwidth of 100m means a sample of 110m or more will be considered eligible overflow sample. Overflow threshold can be configured either as absolute value or in percentage but not both.

Use the no parameter to remove the underflow bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure underflow bandwidth in absolute format in a profile:

The following example describes how to remove the underflow bandwidth configuration from the profile:

Use this command to configure absolute bandwidth range to allow bandwidth re-signalling when underflow threshold and underflow limit criteria matched. This configuration helps to limit the underflow bandwidth reservation update for certain range of bandwidth.

As an example, if the current bandwidth is 500m and the underflow threshold is 10%. So, normally, if all traffic rate samples collected are in the range of 400m to 450m, session will be re-signalled to reserve new bandwidth. However, if underflow-threshold-activate-bandwidth is configured as 300m, then the traffic rate samples in the range of 400m to 450m will not trigger bandwidth update. Only when the traffic rate samples are less than 300m, then it will be considered as eligible sample.

The configuration creates an absolute bandwidth range for underflow samples to be eligible. The bandwidth range for underflow eligibility will be minimum bandwidth (or zero when minimum bandwidth is not configured) to underflow-threshold-activate-bandwidth value. When this command is not configured, there won't be any such absolute range and only underflow-threshold and underflow-limit will be considered for computation, if configured.

Use the no parameter to remove the underflow threshold activate bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure underflow threshold activate bandwidth in a profile:

The following example describes how to remove the underflow threshold activate bandwidth configuration from the profile:

Use this command to configure absolute bandwidth range to allow bandwidth re-signalling when overflow threshold and overflow limit criteria matched. This configuration helps to limit the overflow bandwidth reservation update for certain range of bandwidth.

As an example, if the current bandwidth is 100m and the overflow threshold is 10%. Normally, if a traffic rate sample collected is in the range of 110m to 150m, session will be re-signalled to reserve new bandwidth. However, if overflow-threshold-activate-bandwidth is configured as 300m, then the traffic rate samples in the range of 110m to 150m will not trigger bandwidth update. Only when the traffic rate samples are more than 300m, then it will be considered as eligible sample.

The configuration creates an absolute bandwidth range for overflow samples to be eligible. The bandwidth range for overflow eligibility will be overflow-threshold-activate-bandwidth value to a practical infinity. When this command is not configured, there won't be any such absolute range and only overflow-threshold and overflow-limit will be considered for computation, if configured.

Use the no parameter to remove the overflow threshold activate bandwidth configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure overflow threshold activate bandwidth in a profile:

The following example describes how to remove the overflow threshold activate bandwidth configuration from the profile:

Use this command to configure underflow limit on the auto bandwidth profile. When underflow limit is configured, if the traffic rate samples collected on the associated session consecutively crosses underflow threshold for underflow limit times, then the bandwidth adjustment will be triggered immediately without waiting for adjustment cycle completion. When underflow-threshold-activate-bandwidth is configured, even this criteria is considered to mark a sample as eligible underflow sample.

Only when underflow limit is configured, underflow adjustment may happen before the completion of adjustment cycle. Otherwise, underflow adjustment considered only at the completion of adjustment cycle when all samples found to be eligible underflow sample.

Use the no parameter to remove the underflow limit configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure underflow limit in a profile:

The following example describes how to remove the underflow limit configuration from the profile:

Use this command to configure overflow limit on the auto bandwidth profile. When overflow limit is configured, if the traffic rate samples collected on the associated session consecutively crosses overflow threshold for overflow limit times, then the bandwidth adjustment will be triggered immediately without waiting for adjustment cycle completion. When overflow-threshold-activate-bandwidth is configured, even this criteria is considered to mark a sample as eligible underflow sample.

Only when overflow limit is configured, overflow adjustment may happen before the completion of adjustment cycle. Otherwise, overflow adjustment considered only at the completion of adjustment cycle when a sample found to be eligible overflow sample.

If the traffic rate sample crosses maximum bandwidth, then maximum-bandwidth-exceed-limit configuration comes into picture and by default, a single sample crossing maximum bandwidth triggers bandwidth update. This situation is different from overflow scenario.

Use the no parameter to remove the overflow limit configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure overflow limit in a profile:

The following example describes how to remove the overflow limit configuration from the profile:

Use this command to configure maximum bandwidth exceed limit on the auto bandwidth profile. When maximum bandwidth exceed limit is configured, if the traffic rate samples collected on the associated session consecutively crosses maximum bandwidth for maximum-bandwidth-exceed-limit times, then the action will be triggered immediately without waiting for adjustment cycle completion. When maximum-bandwidth-exceed-limit is not configured, a single sample exceeding maximum bandwidth will trigger an action which is re-signal with updated bandwidth or restart the session with initial or minimum bandwidth based on the action configured.

When maximum bandwidth is not configured, maximum bandwidth exceed limit configuration doesn't have any significance. Overflow limit and maximum bandwidth exceed limits are independent commands with different significance with latter associated with maximum bandwidth.

Use the no parameter to remove the maximum bandwidth exceed limit configuration from the profile.

1

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure maximum bandwidth exceed limit in a profile:

The following example describes how to remove the maximum bandwidth exceed limit configuration from the profile:

Use this command to configure maximum bandwidth exceed action on the auto bandwidth profile. When the traffic rate samples collected on the associated session consecutively crosses maximum bandwidth for maximum-bandwidth-exceed-limit times (or one time if limit is not configured), then the action to be triggered will be decided by this configuration. If not configured, default action is to re-signal the session with maximum bandwidth or ignore if session is already signalled with maximum bandwidth. In any case, user will be notified about the maximum bandwidth being exceeded. However, with exceed action configured as teardown, session will be released and restarted with initial bandwidth or minimum bandwidth if initial bandwidth is not configured.

This action will lead to service interruption if there are no alternate transport. So, this configuration is recommended to be used with full awareness of the impact.

Use the no parameter to remove the maximum bandwidth exceed action configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure maximum bandwidth exceed action in a profile:

The following example describes how to remove the maximum bandwidth exceed action configuration from the profile:

Use this command to configure an action on the auto bandwidth profile when the bandwidth update re-signalling fails on the associated session. By default, if re-signalling fails (3 attempts) for the updated bandwidth, it will be noted down as re-signalling failure and session will continue with its current bandwidth reservation. If severe actions to be taken on such re-signal failure, then teardown action can be configured which will release the current session and restart freshly with initial bandwidth or minimum bandwidth when initial bandwidth is not configured.

This action will lead to service interruption if there are no alternate transport. So, this configuration is recommended to be used with full awareness of the impact.

Use the no parameter to remove the re-signal failure action configuration from the profile.

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure re-signal failure action in a profile:

The following example describes how to remove the re-signal failure action configuration from the profile:

Use this command to configure bandwidth synchronization for primary and secondary sessions of an auto bandwidth profile associated trunk. With this configuration, in case the associated trunk is configured with primary and secondary sessions, every time primary session goes through a bandwidth update, secondary session also will be re-signalled with primary session's bandwidth. Thus, secondary path is determined with proper reservation constraints to ensure it is in the correct bandwidth reserved state when traffic switches to secondary.

Use the no parameter to remove synchronise bandwidth configuration from the profile.

None

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure synchronize bandwidth in a profile:

The following example describes how to remove the synchronise bandwidth configuration from the profile:

Use this command to configure only monitor the traffic rate samples and computation without taking any action. This command can be used to monitor the traffic behaviour without updating the active sessions. With this configuration, in case of overflow, underflow, adjustment cycle completion time computation results, maximum bandwidth exceed, etc., notification is provided without taking any action.

Use the no parameter to remove monitor bandwidth configuration from the profile.

None

None

Auto bandwidth mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure monitor bandwidth in a profile:

The following example describes how to remove the monitor bandwidth configuration from the profile:

Use this command to configure the minimum samples required in an adjustment cycle for bandwidth processing. Sample timers and Adjust timers are executed per auto bandwidth profile and not per associated trunk. Thus, there are scenarios of a trunk going through a bandwidth update few minutes ago and again ends up with adjustment cycle completion processing with very few samples collected. In order to avoid such scenarios, minimum samples required in an adjustment cycle to process the bandwidth shall be configured.

Configuration is accepted in both absolute and in percentage format. This gives user the flexibility to choose the format that suites their need. If sample interval and adjust interval expected to be fixed, then absolute configuration helps providing the requirement of exact number of minimum samples required to process. If exact number isn't important and there are chances of changing adjust interval or sample interval in future, then percentage format can be chosen. However, only one of the formats can be configured.

By default, even if there is one traffic rate sample during adjustment cycle completion, bandwidth will be processed. So, it will be recommended to have this configuration if users are keen on minimum of certain samples to be considered for bandwidth computation.

Use the no parameter to remove the minimum sample configuration from the profile.

1 sample

Auto bandwidth mode

Introduced in OcNOS version 6.5.2.

The following example describes how to configure minimum samples in percentage format in a profile:

The following example describes how to remove the minimum samples configuration from the profile:

Use this command to attach an auto bandwidth profile to a trunk. When the auto bandwidth profile is attached to the trunk, active session will be re-signalled with initial bandwidth configured in the auto bandwidth profile or minimum bandwidth configured if initial bandwidth is not configured. Bandwidth update will be triggered only if there is variation in the bandwidth to be initialized. Attaching or detaching an auto bandwidth profile doesn't trigger any session flap and doesn't cause traffic impact.

When an auto bandwidth profile is associated with first trunk, sample interval and adjust interval timers will start and are stopped when the profile is removed from the last trunk.

Manual bandwidth configuration for the sessions and auto bandwidth profile attach are mutually exclusive and the configuring both of them on a trunk is not allowed.

Use the no parameter to remove the auto bandwidth profile from the trunk.

Trunk mode

Introduced in OcNOS version 6.5.1.

The following example describes how to associate an auto bandwidth profile to a trunk:

The following example describes how to remove the auto bandwidth profile from the trunk:

Use this command to configure on boot sample interval, adjust interval and number of adjustment cycles. When the system is reloaded and comes up, all active sessions of trunks associated with auto bandwidth profiles run a relatively faster adjustment cycle with quicker sample collection to settle the sessions with accurate bandwidth reservation.

By default, sample interval is 1 minute, adjust interval is 5 minutes and the adjustment cycle runs one time. After the adjustment cycle completion, samples of each associated trunks computed to re-signal the sessions with updated bandwidth. Then the auto bandwidth profile based adjustment cycle starts. If user wishes to run the boot up time rigorous sample computation for longer duration or multiple rounds, then it shall be configured. The configurations will apply from system reload if the configuration is saved. Properties of auto bandwidth profiles will not be applied during boot up time computation.

Use the no parameter to remove the auto bandwidth profile from the trunk.

Router mode

Introduced in OcNOS version 6.5.1.

The following example describes how to configure on boot auto bandwidth parameters:

The following example describes how to reset on boot auto bandwidth parameters:

Use this command to force a bandwidth adjustment on a trunk associated with auto bandwidth profile. When the command is executed without bandwidth value mentioned, traffic rate samples collected till the time are used to compute the bandwidth to be adjusted. In case of bandwidth value mentioned in the command, the bandwidth is verified for eligibility and bandwidth update will be triggered.

Privileged Exec mode

Introduced in OcNOS version 6.5.1.

The following example describes how you can force a bandwidth adjustment for a trunk with an auto bandwidth profile:

Use this command to reset the auto bandwidth adjustment cycle by clearing all the traffic samples collected by the associated trunks and by restarting sample and adjust timers. If auto bandwidth profile name is not mentioned, then all trunks associated with any auto bandwidth profile will be reset and computation will start freshly.

Privileged Exec mode

Introduced in OcNOS version 6.5.1.

The following example describes how to restart processing of an auto bandwidth profile:

Use this command to clear the statistics maintained on a trunk associated with auto bandwidth profile. Statistics will be mainly the highest watermarked bandwidth, last adjusted bandwidth, how many times adjustment triggered, status of the adjustment trigger, etc. This command will only clear the auto bandwidth statistics for the trunk and doesn't impact the operation of auto bandwidth including the traffic rate samples collected for the current adjustment cycle.

Privileged Exec mode

Introduced in OcNOS version 6.5.1.

The following example describes how to clear the auto bandwidth statistics on a trunk which is associated with the auto bandwidth profile:

None

Exec mode and Privileged Exec mode

Introduced in OcNOS version 6.5.1.

Example for viewing all the auto bandwidth profiles:

Exec mode and Privileged Exec mode

Introduced in OcNOS version 6.5.1.

The following example is for viewing all the auto bandwidth profiles along with associated trunks:

 

None

Exec mode and Privileged Exec mode

Introduced in OcNOS version 6.5.1.

Example for viewing an auto bandwidth summary of all the trunks associated with auto bandwidth profile:

 

Exec mode and Privileged Exec mode

Introduced in OcNOS version 6.5.1.

Example for viewing the auto bandwidth details of all the trunks associated with auto bandwidth profile