Despite the spec says it MAY include it, I think it would be helpful to determine the XMPP domain on the client, because it is needed for SASL authentication (DIGEST-MD5).
Most times it probably can be extracted from the URL, but that's merely a guess of the real domain, because they are not necessarily the same.
the Openfire BOSH implementation does not include a 'from' attribute, which specifies the XMPP domain in its session creation response:
<body xmlns="http://jabber.org/protocol/httpbind" xmlns:stream="http://etherx.jabber.org/streams" authid="2342472e" sid="2342472e" secure="true" requests="2" inactivity="30" polling="5" wait="60" hold="1" ack="4591532119971033" maxpause="300" ver="1.6">
It's also not included in any further responses.
Despite the spec says it MAY include it, I think it would be helpful to determine the XMPP domain on the client, because it is needed for SASL authentication (DIGEST-MD5).
Most times it probably can be extracted from the URL, but that's merely a guess of the real domain, because they are not necessarily the same.