Establishing a complete glossary of terms related to telephony is a more arduous task than might be assumed.  This is primarily due to the fact that there are as many approaches to telephony as there are to recipes for cheesecake: aside from agreeing that all recipes for cheesecake must call for cheese, anything else goes. 

As a first step for creating our own glossary that targets the wide range of telephony approaches, we’ll list here several related, established glossaries that may point us in the right direction. 

One solid example is the glossary provided by SatNews.com, the on-line newsletter of the Commercial Satellite Industry.  The obvious synergy between telephony and satellite communications results in common terminology, if with slightly different application.  This glossary provides a very comprehensive context in which to examine the terms that are also pertinent to the emerging telephony industry.  Note in particular the treatment of the term “bandwidth.” 
 http://www.satnews.com/GLOSSARY.HTML

For the very detailed terms association with packets, try Burt Lang’s easy-to-follow Glossary of packet terms: 
 

The QOS Forum’s glossary offers more detail than most and is highly readable.  It’s author is Vicki Johnson of Interconnect Technologies Corp. 

The glossary provided by Prime CTI may be the best choice for the purchasing manager in trying to sort through proposals from telephony providers.  It is based on definitions from Newton’s Telecom Dictionary: 

.
.
.
.