Polycom provided me with a self-contained demo package that included a pair of VVX-1500, a NETGEAR switch with POE capability, all the necessary cabling and a USB Kingston Traveler memory stick. This type of demo kit is what they would typically deploy to a small trade show where Internet access was not available. The phones had fixed IP addresses and preset contacts that corresponded to the other phone, making it easy to call from one to the other without even a SIP registrar.
Given this demo configuration, for the first few days I had both phones in my home office and made video calls from one end of the office to the other. From even this most basic experience, I learned a few things about the VVX. For example, the VVX supports multiple wideband codecs, including; G.722, G.722.1 and G.722.1C. That means that it was completely interoperable with my IP650s, which support G.772 based 8 KHz wideband audio capability. Beyond that, they should be interoperable with larger conferencing systems that typically support the two additional wideband codecs.
I also found that between the two VVX units, I could use G.722.1 (aka Siren7), which delivers the wideband call quality of G.722, but at a much lower network bitrate. It requires only 24-32 Kbps, considerably less than even a plain vanilla POTS call using G.711, which is 64 Kbps.
Finally, G.722.1C (aka Siren14) delivers what some call “Super-wideband” audio. Its sampling rate of 28 KHz delivers a usable passband of around 14 KHz, or just about equal to the best FM radio you’ve ever heard.
Beyond the codecs, the VVX hardware is able to deliver superb call quality. The handset is sturdy, with none of the creakiness often found in cheaper hardware. I was surprised to find that the VVX speakerphone is markedly better than my existing SoundPoint IP650s, and comparable to the IP6000 dedicated speakerphones that we use in our corporate conference rooms.
Of course, making use of wideband telephony typically means passing over an end-to-end IP network. The basic setup of the demo setup delivered IP calling on a dedicated LAN so wideband calling was easy. The VVX units were set to automatically start sending and receiving video if the other end of the call was suitably capable. Between the two demo units this was perfect every time. The video was crisp and quick.
The clamshell design allows you to adjust the tilt of the LCD display and camera for optimal viewing. The camera is also independently adjustable so that it can get a well-framed shot when you are directly in front of the phone. A privacy shutter physically disables the camera for times when a video call would be unwanted.
Figure 4: Video call in progress
With two sets of terrace doors, my home office is well lit during the day. This can present a challenge to a videophone or webcam since there is often a bright light source directly behind me. The VVX phones seemed to handle this situation reasonably well.
The VVX-1500 supports two common video frame sizes, both at frame rates up to 30 fps:
- CIF (Common Intermediate Format) = 358×288 pixels
- SIF (Source Input Format) = 358×240 pixels
The phone is able to encode the video streams using H.263, H.263+ (1998) or H.264, which are all standard video codecs for this application. While these are not especially high, resolution is comparable to larger video conferencing systems and CIF and SIF are industry standards that should permit some degree of interoperability with larger boardroom systems.
At present, the VVX-1500 supports the SIP protocol for both audio and video applications. In contrast, many existing video conferencing systems use the older H.323 protocol. Polycom tells me that a coming firmware release will be “dual stack” capable supporting SIP and H.323 simultaneously. This will give the VVX-1500 outstanding utility as an end-point for home office workers who need to participate in video conferences with larger boardroom systems.
I tried some rudimentary interoperability testing using Eyebeam v1.5 and the newly released LifeSize Desktop video conferencing client. Voice calls between Eyebeam and the VVX phones were excellent, with no interoperability issues. However, I was not able to get video calls working with that pairing. Voice calls between the VVX-1500 and LifeSize Desktop were outstanding. This in part because both implement G.722.1C, delivering what the telephony world is now calling “Superwideband,” with high-frequency response up to 14 KHz.
As was the case with Eyebeam, I could not get video calls to work between LifeSize Desktop and the VVX-1500. It appeared that they almost worked, but when the video stream was being set up the VVX would display one frame and then reboot. While they use the same video codec (H.264) I suspect that the major trouble was the video frame dimensions. Although the VVX-1500 supports CIF or SIF frame sizes, the LifeSize Desktop software streams video in the native size of the webcam that it’s using as a video source. It offers no means to resizing the video to a specific size.
The bottom line is that my older Logitech Fusion webcam with LifeSize Desktop was sending 640×480 pixel frames that were simply unsuitable for the VVX-1550. The VVX unit actually displayed the first video frame, then paused and rebooted. While this sounds bad, it is in fact a very good sign. I expect that interoperability with other SIP devices using H.264 encoded CIF/SIF size video would be possible.
Calling from one of the room to the other became boring pretty quickly, so I eventually set up both phones with credentials on my Junction Networks OnSIP hosted IP-PBX account. Both phones registered easily, just as if they were more typical IP phones.
With the phones now registered with an out-of-house SIP server, I could make normal calls to the PSTN and wideband calls to various G.722 capable phones that I have deployed around my employer’s various locations. We have a mix of Polycom, Gigaset and snom gear installed, as well as Counterpath’s Eyebeam 1.5 and the freeware PhonerLite soft phones. I experienced literally no interoperability issues with the VVX phones with respect to voice functionality. All of the usual calling features like hold, transfer, conference, join & split conferences, etc. worked as expected.
The fact that the demo suite included a Kingston USB memory stick suggested that the phones had been licensed with the optional Polycom Productivity Suite. This software option was also described in the IP650 review. I have this on several of the phones that I use every day. While the productivity suite comprises a number of features, I especially appreciate the ability to instantly start recording a call to a WAV file on the USB key. I have found this invaluable to supplement taking notes during a conference call. People who might have missed the call can later listen to the recording and glean more than what my written notes might convey. However, I was not able to find the menu options that expose the Productivity Suite options on the VVX.
In placing calls between the two in-house VVX units, the video capabilities were engaged by default, even though both phones were now registered with OnSIP. Since OnSIP does not proxy the call media, the RTP streams for video and audio did not traverse my router. The phones simply negotiated between themselves and settled upon mutually acceptable video and audio settings. Almost magically, a video call ensued. No special setup required.
Early in August and out of the blue, I received a message from another VVX user who was also a new customer of OnSIP. He asked that I try making a test call to his SIP URI. Dialing his SIP URI into my VVX-1500 I made the call and was happy to find that we had a video call, and also outstanding wideband audio. This was my first experience passing a VVX video call to the world beyond my local network.
Once the call was underway, I looked at the management console for my router and found that the VVX phone was passing about 500 Kbps in each direction, although Polycom specifies that video+audio can consume up to 768 Kbps. On screen the video was clear and smooth, showing the full 30 frames/second. And the video quality was surprisingly good. With the help of Chris Veazey from BlinkMind, I recorded the following short video to show how good the call quality is with such little bandwidth.
In the weeks since, a few other people with VVX-1500 phones have called me. Most were just getting the devices set up and needing to test them by calling an out-of-house SIP URI. Fellow VoIP blogger Dave Michels (http://www.pindropsoup.com) called me while in the process of setting up an evaluation of the VVX-1500 with a Mitel IP phone system. At no time in using the VVX-1500, did I ever experience the loss of sync between the audio and video. This is a classic problem that I have often encountered with video capable soft phones.
While a video call is in progress you can toggle video display modes. The remote party’s video stream can be displayed in a window on the LCD or zoomed up to almost the entire screen. Your outgoing video always remains in a small window in the upper right corner of the screen.
You can also access the phone’s various menus while a video call is active. Your view of the remote party goes away momentarily, but they still see your stream. Hitting the “Home” soft button returns you to the default display with of both video streams.