PEG channel/Channel 99

Good afternoon,

I work for a municipality in North Alabama, and we are having trouble locating the current PEG channel standards/specifications. Our current media encoder is needing to be replaced, and we are looking to replace it with a new media encoder that is still compatible with our current Channel 99 services provided through AT&T. Can you help me locate this? Does AT&T provide a list of vendors they suggest for media encoders? 

Thank you