Your common questions answered.

1) What does a GRX provider offer to a network operator?

The GRX provider assists operators in their GPRS roaming business. GRX providers are facilitators offering the following features:

• Transmission of data packages between operators and their roaming partners

Different connection types between operator and GRX:

• Leased Line (LL) based on Frame Relay, ATM or IP/PPP (based on MPLS in early 2005)
• Tunnelling or VPN connection via public IP (IPSec strongly recommended)
• Virtual Private Data Network (VPN) based on leased line
• Guaranteed compliance with IP addressing guidelines on the Inter-PMN backbone
• DNS root service for customer operators
• BGP-4 routing capability
• Routing of traffic between GPRS networks and/or GRX nodes
• Interconnectivity to other GRXs, governed by Service Level Agreements between GRXs
• Data Security: IPSec (if applicable), anti-spoofing, non-visibility to public Internet, etc.
• Four Classes of Service (CoS) options when MPLS becomes available in early 2005

2) What is needed for GPRS roaming?

• GPRS roaming agreement with one or more operators, or with a Roaming Broker like Comfone (planned or implemented)
• MAP V/3 is mandatory
• TAP3 must be implemented (or contracted from data clearinghouse) to bill GPRS services
• Strategy on ISP or PMN roaming, i.e. access to the Internet in the visited or the home network

3) What does the operator need to connect to a GRX?

• Compliance with IP addressing guidelines for Intra-PMN backbone
• DNS service Intra-PMN
• Border Gateway and preferably a firewall
• AS (Autonomous System) number
• Control over which routes to accept from GRX
• Service Agreement with a GRX provider

4) What about GRX charging principles?

There are a number of charging principles that could apply for GRX. This could include 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.

5) Is a special clearing procedure needed for billing between the GRX provider and the operator?

No, for the time being no special clearing is needed. The GRX provider will issue service invoices.

6) What about clearing between operators?

GPRS operators with roaming relations will use standard GSM clearing procedures between themselves, based on their Roaming Agreements and TAP (Transferred Account Procedure).

7) Which kind of encryption will be used for connections to GRXs and how will the encryption keys be handled?

Encryption is not necessary since the connection uses a private IP backbone. Should operators wish so, they may bilaterally agree on encryption. The GRX is transparent to encryption. In this case the encryption keys are exchanged directly between the operators.

8) Are two operators that contract the same GRX providerautomatically connected to each other?

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.

9) Who pays the connection fee?

Each operators pays for the connection to the GRX. Each operator pays for the use of the GRX services (e.g. fixed port).

10) What is the estimated time needed for establishment of a connection?

• Connection from the operator to the GRX provider via Internet VPN will take aprox. 2-3 weeks
• Connection from the operator to the GRX Provider via Leased Lines based on Frame Relay, ATM or IP/PPP will take approx. 6 weeks
• Connection to other operators connected to the same GRX will depend on the establishment of the bilateral agreement between the operators
  

11) Will every GRX offer DNS routing? Who pays (HPMN, VPMN)?

All GRX providers will offer DNS routing.

DNS Routing is included in the GRX service fee. Every operator pays for DNS routing by using/paying the GRX services.

12) How much time will it take to connect different GRXs?

Generally in the GPRS Roaming Network every GRX node will be connected to the other GRX nodes (either directly or via a third GRX).

At an early stage, if such a connection is not established yet, the time to set it up depends on the finalisation of a Service Agreement between the two GRXs and the time to implement the technical connection between the GRXs.

13) Is security between GRXs guaranteed?

The GRXs take the necessary measures to prevent any intruders from accessing the GRX infrastructure. GRX networks are private and no unauthorised access to GPRS nodes will be possible even though public IP addresses are used.

14) How are the service charges handled in the case of two operators that are customers of two different GRXs? Who pays what (HPMN, VPMN)?

• Each operator pays the service charge of his GRX provider.
  
• Charges between GRXs are included in the GRX service charges. 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
  

15) Who provides DNS routing when two GRX providers are involved?

All GRX providers offer DNS routing. Each operator pays for DNS routing. The amount is included in the GRX service charge.