List of HD compatible telephones

[JTalbert]

I have been doing research and I may be wrong, usually am -) but I think I read somewhere that the hd codec will only work over VOIP systems as copper wire Ma Bell lines at not capable of this codec. Which if this is the case you can have a hd capable phone, bu over copper wire it won't be in HD.

[scottlindner]

That's correct. HD is a VOIP spec. It can only work when both parties have VOIP systems that support the HD portion of the spec.

[TysAri08]

Unfortunately, the manufacturers often times can't even tell you if there phone's are HD capable. I have tried contacting Uniden multiple times on this topic to no avail.

Their model DECT2188 is a great system! It features a corded base model as well as cordless handsets (how many depending on the submodel). The sound is really great and I'm impressed with the overall sound quality using it with the Ooma Telo.

I understand that the cordless handsets won't be HD capable. But what about the corded handset? Is it compatible with HighDef voice? If anyone can answer this for me, I'd really appreciate it!

<http://www.uniden.com/products/productd ... t=DECT2188>

[lbmofo]

Dennis, on page 2, has said these passed the HD test (of the ones they tried):

Uniden CEZ200
Uniden CEZ260
Uniden 1100
Uniden 1260
Uniden 1360
Uniden 3162

[Davesworld]

That's correct. HD is a VOIP spec.

Not exactly but VOIP is likely to make usage more commonplace in the future. g.722 is a fairly old (Approved by the ITU in 1988) ITU standard codec that could be used over a single 64k ISDN B channel just as g.711 (ISDN standard codec) always has done. Some low bitrate codecs such as iLBC are the only ones I can think of that were actually born with internet telephony in mind.

I see mention of copper here but what we speak of as copper is really the last mile. Furthermore, while g.711 is used throughout the PSTN, it only reaches the premises on an ISDN system or via VOIP if so chosen. With POTS, it is decoded at the CO via a narrowband SLIC and piped to the premises as narrowband analog in non ISDN systems. There was a petition that probably was a grass roots movement to urge the usage of wideband SLIC's at the CO and to promote analog phones that could handle 50hz to over 7khz audio and of course use g.722 on the backbone but it was more than just replacing the SLIC's to make it work, some PSTN changes would have been needed as well.

I've had ISDN in the past at two previous residences and it is really far better than POTS even though it was converted to analog via the modem's built in SLIC but it was pure digital up to and through the modem to the SLIC. I could have used a real ISDN phone but most of my calls were to crappy old POTS via friends and family or worse, cellular so I could hear their noise, crackles and pops. POTS should never be used to compare VOIP, technically VOIP with g.711 should be compared to ISDN only but POTS is all most have known so I see why it is often used as a base reference.

It is also very misleading for Ooma to suggest they are the first "phone company" to offer HD Voice (g.722). They are a VOIP provider so "phone company" is pretty fuzzy, I'm sure it's legal to call themselves a "phone company" but very misleading. They are certainly not the first VOIP provider to offer g.722 either, many providers used to offer it but abandoned it before Ooma even existed since most g.722ers will likely use sip to sip and bypass everyone in the process or use a sip gateway. Some such as CallCentric still offer it but like Ooma, it would be within their network dialing normally as most people do. Via sip to sip you can use any codec as long as both ends support it. The only way Ooma could allow sip to sip is if they built it into their web portal so you could have it convert a 10 digit number to a sip url that another person gave you as well as their 10 digit number. Otherwise you would need a very good but hard to configure ATA that allows this. Anyone who owns Siemens SIP phones can use the Siemens provided Giga network to speak via g.722 and use it as a non PSTN gateway. There are other SIP gateways that do this (route sip calls over the internet only) as well. g.722 conferences are very commonplace now for those in the know and with the right equipment. Invitations are often posted in VOIP forums and VOIP blogs.

[Davesworld]

We've now tested the Siemens SL-785 and unfortunately it is no better than any other cordless phone we have tested in terms of transmitting wideband audio...

Aww, man! So the analog base just won't allow it. Now I know why you can get an entire SL785 (analog base plus SL78H handset) for barely more than the SL78H itself. Many just use the SL78H with one of Siemens's IP bases. I do know that the SL78H supports it but now you confirmed that it is not possible with the analog base. I don't see myself buying any more ATA's and analog cordless telephones in the future as it is clear that the analog cordless phones we get are mediocre at best. This is bad news but I am glad you tried it.

[josephmyates]

I don't have a comprehensive list of phones, but I've tried it on the AT&T 993 corded phone with pretty good results. This was actually the phone we used to demo HD voice at CES earlier this year. For this phone, we found the HD voice really only shined through when there was an attached [Plantronics] headset.

Can you elaborate on this phone and the others you listed on Page 2 of this topic?
Am I understanding correctly - that the "HD quality ONLY really shined through when there was an attached [Plantronics] headset"
So the phone "passes though" the HD voice to the attached headset - but not to it's own low quality handset?
So it's not only the compatible phone - but the use of an attached headset that enabled the HD Quality?
Was the attached Plantronics headset one of their corded or cordless models? Which particular model was used during the CES demo?
Would any high quality headset [besides Plantronics] attached to the phones that Bobby listed on Page 2 work?

[Bobby B]

The HD audio sounded much better with a connected Plantronics headset than the standard handset on the AT&T 993 phone.

The phones tested on page 2 of this thread were all tested with their standard handsets (i.e. without an external headset). Without testing, it's tough to say whether an external headset would sound better on all these phones.

[josephmyates]

The HD audio sounded much better with a connected Plantronics headset than the standard handset on the AT&T 993 phone.

The phones tested on page 2 of this thread were all tested with their standard handsets (i.e. without an external headset). Without testing, it's tough to say whether an external headset would sound better on all these phones.

Understood. Thanks.
Was this one of Plantronics corded or cordless headsets?

[Bobby B]

It was a corded Plantronics headset. I'm not sure of the model#.

Understood. Thanks. Was this one of Plantronics corded or cordless headsets?