[Asterisk-Users] One SIP dead, all SIP dead -- sipmedia gone?

[Jay Milk]

I'm having the following recurring problem with asterisk:

When for any reason one of my SIP providers fails to register (i.e.
internet connection dropped), ALL SIP channels fail.  This means that,
for example, when my internet connection is out, none of my internal sip
phones register, and I'm unable to place outgoing calls (through IAX),
or to check voicemail.

Currently (and since yesterday evening), sipmedia.com/myphonecompany.com
is completely off the radar.  No DNS entry found -- not even a
name-server.  They've had this sort of massive failure before, but this
is one of the longest for all I can tell.  While that's a major problem,
it also meant that until I commented out the register =>
sip.sipmedia.com statements, my entire phonesystem was unavailable.

1. Is there any way to get Asterisk to behave less absolute when one sip
registration fails?
2. Is anyone else experiencing the same sipmedia outtage, and/or has
information on when they'll be back?  Tech support seems affected, and
other direct numbers I have go into voicemail.