Confusion over speedfusion and traffic control algrithums

Product Discussion Peplink Balance
2

Speedfusion does get confusing at times.

There is a diagram somewhere that shows the relationship its a pyramid with PepVPN at the bottom as the foundation, the speedfusion hot failover, then speedfusion bonding and then on top of bonding would be traffic management approaches.

  • if you want a secure point to point easy to configure VPN that can cope in a dynamic multi-wan environment but only ever uses a single WAN (recreating the tunnel when a WAN link fails) you need PepVPN.
  • If you want network traffic to be able to move at a packet level between physical WANs you need SpeedFusion Hot failover (single active WAN at any one time)
  • If you want to use multiple WANs at the same time for network traffic you need bonding
  • if you are bonding you can then pick the traffic distribution approach:

  1. Bonding - Aggregate multiple wan-to-wan links as one higher throughput tunnel. (default)

  2. Lowest Latency - Measure the round-trip time of each wan-to-wan link every 2 seconds and select the best one to get lowest latency.

  3. Weighted Round Robin - Send traffic to different wan-to-wan links by a ratio calculated from the user defined WAN upload / download bandwidth.

  4. Overflow - Use the wan-to-wan link with highest overflow precedence for sending traffic. Overflow to link with lower precedence when the current one is congested, or approaching WAN upload / download bandwidth defined by user.

  • if you need to guarantee that a session’s packets get to the other end with the lowest possible latency in a multi-WAN speedfusion VPN tunnel where the data you are sending is small comapred to the total bandwidth available on each WAN link you can enable WAN smoothing which duplicates packets but consumes n * the amount of data sent.

  • if you are worried about packet loss but can’t afford to duplicate all traffic over multiple WANs and you don’t mind a little extra latency you can use Forward Error Correction.

Now if you are using WAN smoothing set to max where all tunnels on all WANs are used for the replicated traffic, then the speedfusion distribution algorithm will be ignored.

However if you are using WAN smoothing set at a lower level and have multiple WAN links then the duplicate packets will be distributed over the WAN links as per the rules. Same with traffic that has FEC applied, its packets will be distributed using those rules too.

So in the case where a lowest latency distribution is used - because typically if you saturate a WAN link latency rises as buffers fill, outbound packets will be sent over the lowest latency WAN first and then as its latency rises over another lower latency link. Speedfusion then is continuously chasing the lowest latency connections. .

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