VOIP Tech Chat → Re: Best adapter and service?

If I went to using IP phones with Callcentric, wouldn't I need a pbx of some sort? Or something like SipSorcery? I guess I see no advantage to using IP phones since they are more expensive plus add another layer between them and the provider. I guess with voip.ms they'd probably work fine.

If you go with Gigaset, Panasonic, Snom or a similar IP DECT system, there is no problem. An incoming call will ring all non-in-use phones (and also signal call waiting, if desired, to in-use phones). You can make a new outgoing call from any non-in-use phone or do a three-way or transfer from an in-use phone. These systems also provide a way to conference an internal handset without significant latency between the internal parties.

If you use standalone phones without a PBX, you'll need to register them to separate accounts (all but one can be free accounts), but you can set up to make them all ring. What gets tricky is that outgoing calls from the free accounts would normally draw from separate PAYG funding. One workaround is to have the main account, without registration, on a second line appearance; you'd use that for outgoing calls. The second method is the reseller interface, which lets you set up multiple accounts fed from the same PAYG balance.

The ones being referenced here for home use basically have the functions of the ata built into the phone itself.

Right, but with Callcentric only one device can register per account. Hence the need for SipSorcery to allow each phone to use the service.

What an insult to the mostly fine job these manufacturers have done. These are true IP phones, unlike e.g. some VTech units, which are cordless phones with an ATA tacked on. The systems mentioned have none of the problems associated with ATAs. You see the caller ID on the first ring, there is no internal echo path or talkoff problem, no waiting for dial tone, etc.Not true! Though SIP Sorcery or similar is useful for aggregating multiple providers, it would only add complexity and degrade reliability, if you are using CC alone or have devices with multiple line appearances. See Iscream's comments here »Porting number to voip.ms or callcentric .

Sorry. Guess meant not an office phone system requiring a pbx.
Yes they are better than a phone plus ata combo.

Stewart, I may be mistaken, but I think that nonymous was making a simple descriptive comment, NOT any kind of criticism.

I have said much the same myself, trying to explain IP phones to neophytes.

First off I should mention that I do use Cisco corded IP phones at work and they perform very well with Boeing's internal network but the claims of sonic nirvana seem to be grossly exaggerated here. Sure it sounds as good as I have heard in g.711 telephony but it still sounds like a phone. I doubt I have sufficient rights to enable the g.722 codec and ask someone else to do the same and we call each other, that's not going to happen.

I personally think that good ATA's get a bum rap here. When I see things like DTMF talk off being blamed on ATA's it gives one a false impression that DTMF talk off exists because it's an ATA not because it happens to be a particular ATA that is notorious for it. Are Kenja and I the only ones who don't use either a PAP or a Spa?

In an IP Phone, does the codec being used in the call remain untouched and undecoded straight through the radio? I don't see how it could be in every case. In some cases where standard DECT is used, it would have to be g.726 between the base and handset anyway. The claims for IP phones leave me with more questions and less answers. To get CID before waiting for a ring does not require an IP phone, it requires an ATA that can be set for early media detection.

Since wideband SLICs have existed for years, there was once a push to start using wideband SLICs at the COs. It didn't get very far though just like we never realized the full capability of ISDN in this country. Some ATA's have wideband SLICS and support g.722 thus being perfectly capable of 8khz audio out the FXS port. Unfortunately, most DECT 6 phones will not support it, not the least of it being caused by the g.726 codec between the handset and base. Many corded phones handle it. Not sure how a Siemens SL785 with it's HSP capability and use of g.722 codec between the handset and base would handle it though.