We have been limited in two choices for free DID: ipkall and Sipgate.
Both have problems. Ipkall cannot do SIP register, 30-day removal, no
CID with GV, unreliable DTFM and call quality sucks. Sipgate does not
offer SIP forwarding and, to put salt on the cut, it is not reliable
when registered with SipSorcery and free SS account allows only one
SIP provider. It stopped giving out DID long ago. Calls suffer from
significant delay.
Now CallCentric offers free DID and it is perfect: in addition to SIP
register like Sipgate, you can also, like ipkall, SIP forward to, say,
username@sipsorcery.com. Of course, you can add the DID to GoogleVoice. I
have made some GV calls via SS and quality is perfect without
noticeable delay.
Even more exciting: it supports CID with name! If no name tighten to
the DID, it'll show the city and state. This feature is disabled by
default, so you need to enable it.
When you register a free CC account, make sure you say "Not in USA",
or your account will be forced to pay 911 fee for any DID including
this free one.
The phone numbers have area codes for NY area. It does not matter, because we only use such a # for GV. If you need a local #, GV is there.