Does WAN optimization help voice/video delivery?

A common question from companies investigating WAN optimization solutions is what can this technology do to improve our voice over IP or streaming video applications?

John Bartlett from NetForecast recently posted a nice write-up at nojitter where he tackled this topic.  The summary of John's observations is that WAN optimization does help, but indirectly.  When the performance of voice or video environments are impacted by bandwidth constraints caused by the sharing of bandwidth with other traffic, WAN optimization can improve the situation by reducing the WAN footprint of the "other traffic".  The result is that there is much more room for VoIP and video.

There are two additional areas where WAN optimization solutions can potentially improve VoIP and video environments.  QoS enforcement is one such area where you give the voice or video traffic priority so that when it competes with other traffic on the network, it gets access to the bandwidth first.  QoS is often performed on the router, but in some cases QoS can optionally be performed from a WAN optimization device such as Riverbed's Steelhead appliance.  In addition to QoS, some WAN optimization vendors provide video delivery services to help with the problem of video taking far too much bandwidth to deliver to endpoints.  For example, Riverbed has partnered with vendors Qumu and Wowza to provide stream splitting capabilities, which is an elegant method of delivering a single stream from a data center over the WAN and splitting the stream to multiple clients at the branch office on the LAN.  The bandwidth savings are absolutely tremendous.

Whether the function is bandwidth reduction, QoS, or video delivery, WAN optimization can indeed be  essential for a successful roll-out of VoIP or video streaming.

I would love to hear from you regarding the impact that WAN optimization has had on your VoIP and/or video streaming applications.