WAN smoothing

I am intrigued to learn about WAN smoothing as described on http://www.peplink.com/technology/speedfusion-wan-smoothing/. I have a similar but not identical need. The type of VoIP drop outs described on that page affect us at certain sites. We don’t have the worlds best internet providers in those locations. Fiber connections are not available. VoIP is frustrating because latency is inconsistent.

Our VoIP provider is not our own company so obviously we can’t set up a SpeedFusion VPN with them. Is there such a thing on a single WAN port that will smooth the connection even at the cost of lower bandwidth? We use a combination of 380, 210, and One routers.


WAN Smoothing is a feature on SpeedFusion tunnel. You need 2 WANs to achieve this. Since you have multiple Balance routers, you may estsblish SpeedFusion from the affected site to HQ (for example) which has no internet connectivity problem. Route Voip traffics to HQ then reach SIP provider (I assume you are using cloud based SIP service).

Hope this help.

I’ve been fighting with this issue for over a year. I even replaced a 210 with bigger model thinking that I might have too much activity for the 210 to handle (wasn’t the problem). Numerous visits from the internet provider (Time Warner) always said no trouble found.

The problem could be documented. If I run a ping from the Peplink router to the internet gateway (which is the cable modem directly attached) the ping times are inconsistent. Out of about 100 pings, 90 of them will be in the 2 or 3 ms range (remember we’re only going to the next device on a 3ft cord), but the other ten are all over the place. 20ms, 50ms, 70ms, some much longer. Those inconsistent times result in stutter or audio drop out on VoIP.

Yestereday I was reading the Peplink documentation on the Cable/DSL optimization feature. I always had it checked-on, thinking it must be a good thing. As I understand the description now, the feature will temporarily delay uplink in order to allow downstream to perform better. If my understanding is correct, might this have been my problem? I turned off the feature and like magic the VoIP problem went away. Hooray! I ran that ping test literally 200 times and every one is perfect.

Please elaborate if my understanding of how Cable/DSL optimization works is correct I suggest your next user guide point out that this feature may not be compatible with VoIP.


Thanks for your efforts. When Cable/DSL optimization was enabled, certain packets for upload will be prioritized in order to smooth up the entire session. I suspect Voip packets were queueing up when this option was enabled. But this is rarely happen unless you have many session initiated from LAN. May I know your upload was congested? What is the top services in your network?

Anyway thanks for sharing! :up:

That location has few employees and the lowest use of all our stores. We have other locations with much higher load. I can only assume the cable/dsl optimization algorithm is more agressive than I would like. Since disabling cable/dsl optimization at all our locations two days ago, I am receiving unsolicited messages from users saying 'wow the internet is much faster, what did you do?" They did not even know I made a change.

At one location the manager runs a large number of print jobs every morning. The server for those jobs is at a different location connected by Pep VPN. This morning he sent me an email explaining that the printers usually get delayed multiple times through the jobs but now the last two days they complete without interruption. He wondered if I did something to cause that.

I am suggesting you consider that this option should not be on by default, and the user select it only if needed to fix a problem, and a better explanation of what it does in the documentation.


Since disable Cable/DSL optimization help, I suggest remain as current. Please enable Qos as well if needed.

Anyway thanks for your suggestion. We will look into your suggestion.