Subject: SDP (RFC2327) query

From: Vikram Visweswaraiah <[email-masked]>
Date: Wed, 15 Sep 1999 11:02:43 -0700 (PDT)

I'm seeking a minor clarification reg. few fields in the SDP rfc.

According to the RFC:

- email field "e=" is optional
- phone field "p=" is optional

Then, in the discussion titled `Email Address and Phone Number' the following
points are mentioned:

o Either an email field or a phone field must be specified. Additional email and
phone fields are allowed.

o If these are present, they should be specified before the first media field.

o More than one email or phone field can be given for a session description.

I'm confused on how to interpret this.

Is it true that atleast one of `e=' or `p=' should be present? If so, then why
the notion of `If these are present..'? Then if BOTH are optional, i.e a valid
SDP message can omit both `e=' and `p=', then why mention `Either an email field
or a phone field must be specified.'?

Thanks
:=Vikram