CNAME Is Not An Email Address (Q3)

The information in this article applies to:

Some vendors use the user's email address as the value of the CNAME SDES item in RTCP. However, 9.6.4.1/H.225.0v2 states, "The host name is not necessarily identical to the one in the participant's electronic mail address." Moreover, it says, "the CNAME should be derived algorithmically and not entered manually, when possible." For example, although I may have entered my email address as "Paul.Long@usa.net", I may have logged onto a system with user name, "plong", and my host name may be "choochoo.smithmicro.com". In this case, my canonical name would be "plong@choochoo.smithmicro.com" and not "Paul.Long@usa.net".

This would only be a problem for endpoints, such as an MCU or third-party monitoring equipment, that require sources to use unique CNAMEs. For example, if the same email address is specified at multiple endpoints, all but one may be locked out of a centralized multipoint call.