Forward Error Correction and Loss FAQ - Understanding-Forward-Error-Correction/Forward-Error-Correction-and-Loss-FAQ

Understanding Forward Error Correction

ft:locale
en-US
ft:sourceName
Paligo_Prod
Document Type
Concept
Article

1.

Is forward error correction (FEC) bi-directional (site to NetCloud Exchange Service Gateway and NCX Service Gateway to the same site)?

Yes, FEC is bi-directional.

2.

What happens with FEC on multiple links? How is FEC split if multiple links are configured?

FEC is applied to the WAN link to which the destination resource (site or named resource) is bound according to the traffic steering rule including the SLA, Multi WAN Type, and WAN Selector criteria. FEC applies to each link that is selected for the flow.

3.

Is loss included in the traffic class setting as a condition of WAN path selection?

Not in the current release.

4.

How much bandwidth does FEC take? Is it 20% additional or are FEC smaller representative packets?  Is this 20% additional load in the first iteration of FEC or 20% FEC packets?

In the current release, 20% extra packets are added.

5.

On which applications does FEC work best?

FEC works best with traffic that is loss sensitive. The administrator needs to use traffic-steering rules to identify such traffic and assign a traffic steering rule that uses a FEC-enabled traffic class.

6.

What happens to “Unknown” traffic or no application match?

All unknown traffic is considered as belonging to the Best Effort traffic class.

7.

Is loss only collected on the NCX Service Gateway?

Though the NCX-enabled router and the NCX Service Gateway both determine the loss when receiving traffic, the collation of loss related statistics occurs at the service gateway.

8.

How often is loss collected?

It is based on the flow reaching the NCX Service Gateway. The interval of reporting is five minutes.

9.

Is FEC smart enough to understand loss may be cause by saturation of a circuit?

No