In a method of configuring connection identifier (CID) update information
in a broadband wireless access (BWA) communication system where each
service between an mobile station (MS) and a base station (BS) has a
unique CID, a registration request message is received from the MS,
requesting updating of at least one old CID used for the MS. The CID
update information is configured to include a bitmap area indicating
whether a service corresponding to the at least one old CID is available,
and a new CID area including at least one new CID in correspondence with
a predetermined bit value in the bitmap area.