SDWAN and FEC

[carl_townshend]

Hi All

Can anyone talk to me about FEC (forward error correction) at the packet level ?

I believe many SD WAN products now use this and I believe it can have really good effects on a lossy / high latency network.

Does it work?

How does it work?

Does Viptella / Meraki use it?

Cheers

[Giuseppe Larosa]

Hello @carl_townshend ,

for FEC at packet level you can refer to the following links:

https://tools.ietf.org/html/rfc6363

https://link.springer.com/chapter/10.1007/978-0-387-34986-2_8

from the second link:

Packet level forward error correction can be implemented by transmitting M redundancy packets after each set of N regular packets, so that all packets can be reconstructed if at least N out of N + M are received

according to the following link it is supported on VIPTELA SD WAN if using IPSEC tunnels

https://sdwan-docs.cisco.com/Product_Documentation/Software_Features/Release_18.4/06Policy_Basics/04Centralized_Data_Policy/01Configuring_Centralized_Data_Policy

Hope to help

Giuseppe

[carl_townshend]

Does it really work? how effective in real life is it, do people get good results?

[Giuseppe Larosa]

Hello @carl_townshend ,

I have no direct experience of this packet level FEC.

However, fot the way it works you can reduce packet loss at the price of an higher latency as you send M+N packets insteaf of N packets only.

So my guess is that if your WAN links have losses and have also an high latency this feature may not be so effective.

Hope to help

Giuseppe