H.323 and G.723.1 are just a small part of the picture, and they really don't have much to do with connecting to the PSTN. They are ITU-T standards that cover the codecs (compressors/decompressors) only, i.e., the compression of digitized voice.
As a telecom manufacturer, you can't just willy-nilly connect anything you want to the PSTNs (public switched telephone networks). There is a hierarchy of standards that you have to comply with:
International -- standards from ITU (International Telecommunication Union, part of the United Nations) and ISO (International Standards Organization)
U.S. -- ANSI standards (American National Standards Institute), plus also you need a FCC registration (see Title 47, Code of Federal Regulations, Section 68 for the technical specs)
phone company -- U.S. RBOCs make you comply with standards put out as Bellcore TRs (Bellcore was formerly known as AT&T Bell Labs).
There are a huge number of standards that have to be complied with before a manufacturer is allowed to interconnect their equipment to the PSTNs. For example, there are ITU-T standards on signal quality (they even specify how loud you can be!), physical interfaces, signalling (ask Val how much fun R2 can be...), numbering plans (for example, the IP address of talk.techstocks.com is 207.183.154.206 -- how do you map that into a country code, area code, and phone number), switching, billing, network maintenance, etc. You might try browsing around at itu.int to see what I mean.
Real life example -- I have an upcoming project with a Brazilian phone company (Embratel) where our equipment has to connect to phone switches made in France by Alcatel. I'm going to have to comply with a pile of standards, like ITU-T M.3100, ISO 10164-4, etc. to get this to all work together, but that's what you have to do when dealing with phone companies.
Paul M. |
