Siebel 7 and Genesys 6.5 Inbound

[Alex]

Hi,
on GPlus adapter for Siebel 7 inbound voice configuration about Alcatel 4400 I read this sentence:

Genesys recommends the following configuration changes for the Alcatel A4400 switch :
1 Set the TServer option agentsubstitute to On.
2 Define the Gplus Voice Adapter for Siebel 7 in the configuration for the agentfs extension.
Note: Do not configure the agentfs position with the TServer option agentsubstitute set to On because in this configuration, TServer performs the required substitution of an agentfs calls to another agentfs positions.

What does this mean? Expecially on point 2? It is not necessary to configure agent position for every login and with the same number as done without Siebel Adapter?
Could someone explain this to me?
Thanks