I just installed Google Talk and so far I can't tell what codecs it supports or what protocol it is using for the voice. I know the IM portion is using Jabber, which means you can configure third-party IM clients such as GAIM or iChat to work with Google Talk. I did a port scan and 5060 isn't open, so it isn't using the standard SIP port. Checking Google Talk's site, I found this with regards to SIP:
4. Do you plan to support other real-time communication protocols?
Google Talk supports XMPP with the beta release. We plan to support SIP in a future release. Additionally, we will evaluate other protocols as appropriate, to continue to deliver on our commitment to open communications.
Well, no SIP for now. Nevertheless, this software clearly looks like an attempt to go up against Skype. The user interface is very simplistic, either modelling after Google's "simple" web home page or they're just getting this product's feet wet before they add all the "bells & whistles". It does have one-click access to your Gmail email account (launches default browser) and it also features a small window popup in the lower right system tray when you receive an incoming emaiil or instant message. It also appears that similar to Google's Gmail email service that you can save your Chat history. Unlike Gmail however, it appears you can opt-out of recording your chat sessions. To logon you simply use your Gmail account. Looks like the GMail invites should see a spike due to Google Talk. Wonder if people are still selling Gmail invites on eBay?
I'll report more after I make a test call.
Update: Made my first Google Talk Call
The sound quality was excellent and latency was very minimal. I actually made a PSTN call and a Google Talk call and held the microphone up to the PSTN phone I was using. On the remote end I had the person turn his external speakers up so I could hear when my voice came through. I did some simple counting and almost immediately I could hear my voice come out of the remote speakers, into the remote callers phone handset, over the PSTN, and then to my phone handset. Pretty amazing how minimal the latency was considering it was round trip.My only complaint is that you can't right-click a contact and initiate an immediate Google Talk voice call. You had to start a chat session first - a bit annoying. Anyway, here's a screenshot of the call:
Update: Found this regarding codec support: Wow, they're supporting Global IP Sounds amazing codec right out of the gate! It's no secret that one of the reasons Skype sounds so damn good is the Global IP Sound codec.
Today, Google Talk supports the following standard voice codecs: PCMA, PCMU, G.723, iLBC. We are also evaluating the Speex codec. We also support codecs from Global IP Sound: ISAC, IPCMWB, EG711U, EG711A
And check this out, unlike Skype they will be working with third-party VoIP softphones/IM clients. This is also from the Google Talk page:
2. Whom are you federating with?
As a first step towards fulfilling our commitment to federation, we will federate with EarthLink and Sipphone, service providers who share our belief in enabling user choice and open communications.
3. When will federation with EarthLink and Sipphone be available?
We do not have details at this time on when federation will be enabled. But we are working closely with Earthlink and Sipphone to federate EarthLink's Vling service and Sipphone's Gizmo Project with the Google Talk service as quickly as possible, while offering the best possible user experience.
Some key points about Google Talk:
- Works with other Jabber clients but IM only - no voice support via 3rd party apps
- No SMS support
- No file transfer support
- No Jabber-to-Jabber intra-server communication
- No Mac or Linux client (Windows only)
- Can't organize contacts into groups
- Can rename the clients via right-click context menu but not a single-click rename
- Good voice quality
- Uses a proxy server run by Google (eavesdropping concern for some)
- Can't right-click a contact then initiate a voice call
- No video support
- No conference chat or conference Voice Chat
- No PSTN capability (i.e. SkypeOut) (yet)
Google Talk Just a Me Too Product for now
Check out the screenshots of the interface.