What is the call bumping issue?
Posted by Gabriel Yu on 14 March 2008 05:34 AM
There appears to be some incompatibility between DrayTek and Telstra's
ISDN equipment or service which results in Call Bumping not operating
fast enough for a phone call to be established. One of the "B" channels
is dropped, but by this time the caller hears engaged or unavalable
tone. For outgoing calls you can replace the telephone receiver then
pick up immediately to get the outside line. If the incoming caller
rings back straight away the call will go through - but most callers
won't know to do this.
DrayTek have significant expertise with ISDN,
NBS considers this a serious issue and have decided to
The effects of Call Bumping will be minimised or avoided if the customer :