How to test the quality of an IP Phone?
Submitted by johnny on Mon, 06/09/2008 - 7:50pm.
With so many IP Phones available in the market, other than the brands and first usage appearance,
Any one knows how we could test the quality of an IP Phones under different cases even by using equipments or software to do so?
Just don't have an idea about the procedures.
What type of quality?
Mon, 06/09/2008 - 8:09pm
Are you trying to test voice quality? It's a very involved process to measure objectively.
If you are really interested Google "Perceptual Speech Quality" it's really the parlance of manufacturers.
Beyond lab measurements most evaluation is purely subjective.
Scott
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Scott
aka "Skyking"
They are almost the same
Mon, 06/09/2008 - 11:16pm
All IP phone should make pretty much the same voice quality on the handset. You can barelly tell the difference unless you are an extream picky guy. On the speaker phone, because different verdor uses diffenent speaker. It will sound differently on different brand. They most likely sounds different but all acceptable. Some speakers make lower pitch sound, and some speakers make higher pitch sound. It's all up to how you like its sound. Somebody likes the lower pitch sound speakers and claim the higher pitch sound speaker had bad quailty is not fair. The phone itself should not have an quality problem before it gets ship out the factory. The sound quality on VOIP phone is 100% depending on the quality of your network.
My take...
Wed, 06/11/2008 - 7:31pm
I have to disagree that "all IP phones" should have relatively the same handset quality. Some of the higher end phones have better amplifiers and/or speakers, and therefore the sound will be more "full" than a low-grade model. This is not to say that low-grade handsets suck - most are adequate for the average user.
I do agree that speakerphones is where a major differentiator lies - but it encompasses more than just the speaker. Better phones have significantly better microphones and have also been engineered to avoid echo issues in speakerphone mode.
I would also disagree that the quality of the network affects call quality in any way. As long as you have a functioning network and are not maxing it out (or have implemented QOS), call quality will always remain constant. Whether you have a $20 no-name switch or a $50,000 routing & switching infrastructure, call quality will not change - after all, digital is digital. Where you get into trouble is when your network is not up to par & it begins to drop packets or induce significant latency. I'm sure that's what was meant, but I didn't want anyone to get the wrong idea.
The main difference between a $50 (e.g. Grandstream) phone and a $400 phone (e.g. Cisco) is going to be the feature set available on the phone. While, yes, there IS a difference in call quality, the things you're typically paying for are features. For example, color LCD screens, significant call logging capability, XML compatibility, configurability, etc. I love my new Cisco 7965 phones with custom backgrounds, custom ringers, color LCD, tons of bells & whistles, excellent call quality and almost limitless XML integration with couple custom apps that I'm building.
Cheers...
I would like to add:
Fri, 06/13/2008 - 4:28pm
that not to mention a 50$ voip phone (no names mentioned), i can notice a distinct and very obvious difference and especially on the HANDset - between my cisco 7975 and 7960/7940 phones. The call quality on the 75's (as well as the new 65's and 45's) are far and noticeably superior to the lower end ciscos. In my humble personal opinion, there potentially is equally that gap between the lower end cisco phones and other units.
Actually...
Fri, 06/13/2008 - 10:54pm
That's probably because Cisco is shipping a new handset with the 7975. The 7970/7971/7940/etc use a different one.
I don't know WHAT the difference is as I've only seen a 7975 once. I did notice a couple of external differences though, and suspect that they changed the insides as well. (take a look at how the handset cord plugs in. The 7975 handset socket is set deeper into the base and as such, is incompatible with most "Cord De-tanglers")
That is the so called "wide
Fri, 06/13/2008 - 11:06pm
That is the so called "wide band" handset. If you look in the phone menu options you can find a setting. I do not know if there is an XML tag to assign this. I also have not looked at the spec's to see if any new CODEC's have been introduced.
The wideband handsets work with the 7971G-GE, it is the first phone that I noticed this in the options. You can search and find pictures of them on the Internet. Besides the recessed jack the holes are different on the ear and mouth piece.
Scott
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Scott
aka "Skyking"
youre right Scott
Mon, 06/16/2008 - 5:28pm
I have 75/65/45 phones at home now and the wide band sounds like you are actually talking to a person rather than to a person on the phone. It brings a much larger spectrum into the play which i think is an increased quality in handset microphone and speaker at worst case.
There are a host of new settings (which i havent figured out yet) in Media Configuraiton which include Recording Tone local/remote volumes, duration, wideband headset, Enterprise Advertise G722/Device Advertise G722 and Headset Hookswitch Control. Amongst quite a few others i havent seen on the 7970's.
Member Since:
2006-08-29