Dual-ended continuous monitoring is fundamentally the same as singled-ended. The differences are that dual-ended paths:

  • require a monitoring point as the path target,
  • use UDP instead of ICMP,
  • there are some quirks with diagnostics,
  • and the path performance page displays and one chart for each direction.

What about latency and RTT? RTT doesn’t display info for both directions because the metric already considers both directions; likewise for latency, since it’s derived from RTT.

Create a dual-ended path

A dual-ended path is one that is monitored independently in both directions. For this the path must have a monitoring point at both ends. Monitoring in both directions is useful for paths that have links that are known to be asymmetric, like the connection to your ISP; or where the path is equally burdened in both directions, like for video conferencing and voip.

In the Path Setup Wizard, there are three opportunities to configure a path as dual-ended:

Two of your own monitoring points

  1. Select two monitoring points in Step 1 of the Path Setup Wizard.
  2. In Step 2, select ‘set monitoring points as endpoints’.
  3. From the ‘instrumentation’ drop-down, select ‘dual-ended’ or ‘single and dual-ended’. The latter option simply creates two paths, which you can preview in Step 4.

One of yours, one of ours

Instead of using two of your own monitoring points, you can use an AppNeta WAN target instead.

  1. Select one monitoring point in Step 1.
  2. Complete the connectivity test in Step 2 because it’s tied to your opportunity to make the path dual-ended in Step 3.
  3. In Step 3, check ‘dual ended path’.
  4. You’ll then have the option of naming the inbound and outbound directions; most users leave the defaults.
  5. In Step 4, the paths that can be dual-ended are marked in the right-most column.

In Step 4

  1. The right-most column indicates whether the path is dual-ended. Check or un-check this box to make it single or dual-ended.
  2. The path name does not automatically update, so the if the path name includes ‘(single)’ or ‘(dual)’, be sure to update it.

Change a path to dual-ended

  1. Navigate to Delivery > Network Path List.
  2. Select 50x50_trans.png > Configure.
  3. Click ‘create this path with dual-ended instrumentation’.
  4. Name the inbound and outbound directions of the path (optional).
  5. Click ‘submit’.

Customize the UDP port range

Monitor engineered traffic patterns with AppNeta Performance Manager (APM) by specifying the port range used for dual-ended paths. Using a custom, narrow port range enables network admins to classify UDP probes between source and target using extended ACLs so that the probes can be influenced by policy-based QoS, policy-based routing, and port-based traffic filtering.

Web admin

  1. Log in to web admin.
  2. Appliance Configuration > Sequencer Configuration.
  3. Ports can be customized by uncommenting ‘# UDP Port Range: 45056,49151’.