The relevant RFC is here: https://www.ietf.org/rfc/rfc3261.txt
> SIP URIs [have] a similar form to an email address, typically containing a > username and a host name. In this case, it is sip:b...@biloxi.com, where > biloxi.com is the domain So in the URI sip:b...@biloxi.com, the username is "bob". This report refers to a "username" as the email address used for creating the account. If the username itself contains an "@" character, it would have to be escaped, according to the RFC: > For each component, the set of valid BNF expansions defines exactly which > characters may appear unescaped. All other characters MUST be escaped. > For example, "@" is not in the set of characters in the user component, so > the user "j@s0n" must have at least the @ sign encoded, as in "j%40s0n". So to answer this question: > Given that SIP account names can not contain at signs, what do you suggest > the program do when such username is entered? The answer is: escape it as "%40". But in the meantime, this issue can be worked around by manually giving the username with the @ escaped in this fashion.
