A 
connection broker (44), located between lower-level 
system entities (16, 58, 264) associated with a 
narrowband-
broadband interface (250) and a call 
server (18) that controls call connection across the 
narrowband-
broadband network, contains a memory (251) that stores connection-related information and protocol 
converters. The 
connection broker (44) accesses the protocol 
converters to interpret control messages received from the call 
server (18) and, where necessary, transposes messages for the call 
server into a standardised format for use over a uniform fabric application interface (66). Control messages pertaining to connection paths within the 
narrowband-
broadband network (250) and relayed via the 
connection broker (44) are appropriately phrased (by the connection-related information and protocol 
converters) to ensure that meaningful information and instruction is communicated between the call server (18) and the lower-level 
system entities (16, 58, 264). Use of the protocol converters therefore enables connection attributes and network operation and configuration to be altered and advised in-call by having the connection broker (44) both change connection-related information and communicate any change in 
network configuration to the call server and lower-level 
system entities, as appropriate.