There are a number of charging principles that could apply for GRX including volume (bytes transferred), geographical length of path or fixed port with guarenteed capacity. Comfone has made its offer as simple as possible and has consequently chosen fixed port charging.
GPRS operators with roaming relations will use standard GSM clearing procedures between themselves based on their Roaming Agreements and TAP (Transferred Account Procedure)
Encryption is not necessary because the GRX is transparent to encryption and the connection uses a private IP backbone. Upon operator request, bilateral encryption agreements can be set and the encryption keys exchanged directly between the operators.
No, there is no automatic roaming connection. Both operators need a service agreement with the GRX provider, a connection to the GRX provider and a roaming agreement between themselves.
Generally every GRX node is connected to all other GRX nodes in a GPRS roaming network (either directly or via a third GRX)
If a connection is not yet established, the time to set it up depends upon the finalisation of a Service Agreement between the two GRXs and the time to implement the technical connection between the them
GRXs take necessary measures to prevent any intruders from accessing the GRX infrastructure and because GRX networks are private, no unauthorised access to GPRS nodes will be possible even though public IP addresses are used
Each operator pays the service charge of its GRX provider
Charges between GRXs are included in the GRX service charges but the GRX provider has the option to charge differently if the data traffic was routed directly to an operator or via another GRX
The GRXs charge and pay the service used between them as defined in the SLA between the GRXs
