This article originally appeared in the October 2010 issue of INTERNET TELEPHONY.
Yealink, a Chinese manufacturer of IP phones, is starting to make inroads in the U.S. market with its line of VoIP phones. Several months ago Yealink (News - Alert) sent me a Yealink SIP-T28P IP phone to review. The SIP-T28P is a six-line phone sporting a large 320x160 LCD screen and has full HD voice support (wideband codec, wideband handset, wideband speakerphone). The SIP-T28P was one of the first IP phones to support the G.722 wideband codec that is now all the rage in the VoIP market.My first impression of the SIP-T28P was that I liked the large LCD and the sleek ergonomic design, which had large, easy to press buttons and a useful four-way arrow navigation keypad.
I connected it to our network and logged into the Web admin page to configure the phone. The Web interface was easy enough to navigate. I had no trouble adding the SIP credentials, configuring the NTP server, adding speed dials, and other various configuration options.The Web interface displays a message when the phone is registered so you know immediately if you put the SIP credentials in correctly. I have to say, I really loved how every change I made didn’t require a reboot. I've never tested a phone that didn't require a reboot, especially after putting in the SIP settings. Even after putting in the SIP settings on the SIP-T28P, I didn't have to reboot. It auto registered immediately.In any event, after registering the phone on an Asterisk (News - Alert) based IP PBX I made a test call. The voice quality was excellent. I switched over to speakerphone mode, and it too had excellent quality with no echo. I definitely noticed a difference with the wideband HD support on this phone.
From the Web interface you can manually add contact names or even import them. This is useful if you want to convert the caller ID phone number to the person's name. You also can add them to the blacklist section and the caller with automatically be sent to your voicemail.
The dial plan is a little bit different than some of the other IP phones I'm used to. It does allow for matching a digit or a range of digits and you can replace digits, but I couldn't seem to figure out how to send a terminator key to end the dial string and cause the phone to dial immediately. I could manually terminate the dial string by pressing the # key on the phone, but I find that a bit of an annoyance. I prefer to just dial the phone number and have the phone recognize when I press the last digit (by matching the dial plan) and simply dial the number.
There was a bit of a workaround. Under the dial plan was a feature called Dial Now. I was able to add my phone's extension to the list (149). Then when I dialed from the Yealink to x149 it dialed it without requiring me to press #. Still, it was about a 0.5s delay before it would dial and not quite instant. Also, this workaround is only for 10 phone numbers and not for matching any phone number you dial.
The hotline feature is pretty nifty, though it probably has very niche applications. You simply put a phone number into the hotline field and it will instantly dial that number when you pick up the handset (both internal extensions and outbound numbers work). This is great for CEOs/executives to reach their personal assistants instantly, and vice versa.
Another interesting feature that ringtone fans will certainly like is that you can upload your own ringtone to the phone. The phone supports NTP servers for keeping the phone's clock accurate and it supports daylight savings time. It also supports auto provisioning via TFTP/FTP/HTTP/HTTPS. It's worth mentioning that the SIP-T28P supports both PoE and the use of an AC adapter. One last cool feature is that you can customize the Yealink logo using your own grey scale image.
Overall, I really liked the SIP-T28P. The large LCD was very easy to read and the HD components (wideband codec, handset, speakerphone) truly gave this phone superb sound. Both the Web interface and the LCD were very easy to navigate to perform functions or change configurations. The phone never crashed on me once in the few months that I tested it. It's very reasonably priced at $189 for such a feature-rich HD phone, and I wouldn't hesitate to recommend it.
Tom Keating is Vice President and Chief Technology Officer at Technology Marketing Corporation, and Executive Technology Editor/SEO Director for TMCnet.com. To read more of Tom’s articles, please visit his columnist page. He also blogs for TMCnet here.
Edited by Stefanie Mosca