Inbound Call Channel Allocation Method

Parameter group

VoIP SIP Signalling

Access level


Possible values

Allocate calls from highest available channel (using 'linear' allocation)
Allocate calls using 'round robin' method
Allocate calls for D2IS
Allocate calls balanced across trunks
Allocate calls from highest available channel within T1/E1 limits


Allocate calls from highest available channel


This determines how Blueworx Voice Response allocates an incoming SIP call to a trunk and channel.

The default is by searching for the first free channel starting from the highest numbered channel and working downwards (from Trunk 16, channel 30 to Trunk 1 Channel 1). For some systems which use CTI (Computer Telephony Integration) this means that highest-numbered channels are reused very quickly and also there is an uneven spread of active channels across the complete range.

For more even channel allocation, the Allocate calls using 'round robin' search method begins at the next lower-numbered channel from the one last allocated (wrapping first to last).

To ensure the call load is spread over the adapters on the system, specify Allocate calls balanced across trunks. You must use this method if using iLBC compression.

The Allocate calls for D2IS method is for use with the Genesys supplied D2IS custom server. The allocated trunk and channel are based on the dialled number. The first three digits of the dialled number are ignored. All digits after this are converted into a trunk and channel number. The trunk is derived from the remaining digits of the dialled number divided by 100, the channel is the remaining digits of the dialled number, modulo 100. For example:

Note: Using the 'D2IS' method, it is not possible to specify an application profile number to state table mapping. However, Number-to-application (NumToApp) mappings are possible if the first three digits map to a particular application, for example, 123001001 could be defined as 123* and 987001001 could be defined as 987* in NumToApp mappings.

Linear CTI will always select the highest available channel obeying both the license limit and the original E1/T1 channels per trunk limit. This is important for CTI protocols that use the trunk/channel numbers.