GPRS architecture works on the same procedure like GSM network, but, has additional entities that allow packet data transmission. This data network overlaps a second-generation GSM network providing packet data transport at the rates from 9. Along with the packet data transport the GSM network accommodates multiple users to share the same air interface resources concurrently. GPRS attempts to reuse the existing GSM network elements as much as possible, but to effectively build a packet-based mobile cellular network, some new network elements, interfaces, and protocols for handling packet traffic are required. A variety of MS can exist, including a high-speed version of current phones to support high-speed data access, a new PDA device with an embedded GSM phone, and PC cards for laptop computers.
|Published (Last):||11 February 2013|
|PDF File Size:||19.20 Mb|
|ePub File Size:||14.47 Mb|
|Price:||Free* [*Free Regsitration Required]|
It also includes information about configuring access points on the GGSN. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online. On the Cisco series router platform, this interface is a physical one. To configure a physical Gn interface to the SGSN that supports Fast Ethernet on a Cisco series router, use the following commands, beginning in global configuration mode:.
If this keyword is omitted, the configured address is the primary IP address. Configuring To configure a subinterface that supports IEEE Defines the encapsulation format as IEEE Step 2 To verify that a physical interface is available, use the show ip interface brief command.
Step 5 To verify that the subinterface is available, use the show ip interface brief command. A static route establishes a fixed route to the SGSN that is stored in the routing table. If you are not implementing a routing protocol, such as OSPF, then you can configure a static route to the SGSN, to establish the path between network devices.
To configure a static route from an interface to the SGSN, use the following commands, beginning in global configuration mode:. This is the subnet mask of the SGSN network. To configure OSPF, use the following commands, beginning in global configuration mode:. Enables OSPF routing, and enters router configuration mode, where process-id specifies an internally used identification parameter for an OSPF routing process.
The process-id is locally assigned and can be any positive integer. A unique value is assigned for each OSPF routing process. It can be specified as either a decimal value or as an IP address. If you intend to associate areas with IP subnets, you can specify a subnet address as the area ID. The following example shows a partial configuration of an OSPF configuration for the The following example shows a partial configuration of a configuration to the SGSN:.
Successful configuration of access points on the GGSN requires careful consideration and planning to establish the appropriate access for mobile sessions to external PDNs and private networks. An APN identifies the part of the network where a user session is established. The network ID can be a maximum of 63 bytes and must contain at least one label.
A network ID of more than one label is interpreted as an Internet domain name. An example of a network ID might be "corporate.
The operator ID contains three decimal-separated labels; the last label must be "gprs. The maximum length of an APN is bytes. The access point list contains one or more access points. The GGSN always uses real access points to reach an external network. Because the GGSN always uses real access points to reach an external network, virtual access points should be used in combination with real access points on the GGSN.
GGSN Release 3. This section describes the basic tasks that are required to configure an access point on the GGSN. Detailed information about configuring access points for specialized functions such as for virtual APN access are described in separate sections of this chapter.
The GGSN software requires that you configure an entity called an access point list. When you configure the access point list in global configuration mode, the GGSN software automatically associates the access point list with the virtual template interface of the GGSN. Therefore, the GGSN supports only a single access point list. A GPRS access point list defines access points and their associated characteristics, and an IP access list controls the allowable access on the router by IP address.
You can define permissions to an access point by configuring both an IP access list in global configuration and configuring the ip-access-group command in your access point configuration. To configure the GPRS access point list and configure access points within it, use the following command, beginning in global configuration mode:.
Specifies a name for a new access point list, or references the name of the existing access point list, and enters access-point list configuration mode. You need to define access points within an access point list on the GGSN. Therefore, before you can create an access point, you must define a new access point list or specify the existing access point list on the GGSN to enter access-point list configuration mode.
When you create an access point, you must assign an index number to the access point, specify the domain name network ID of the access point, and specify the type of access point virtual or real. Other options that you can configure for an access point are summarized in the "Configuring Other Access Point Options" section.
To create an access point and specify its type, use the following commands, beginning in global configuration mode:. Specifies an index number for a new access point definition, or references an existing access point definition, and enters access point configuration mode. This is the default value. Use real access point types to configure the GGSN for direct access to a particular target network through an interface.
If you have configured a virtual access point, you must also configure real access points to reach the target networks. The GGSN supports configuration of access points to public data networks and to private networks. The following sections describe how to configure different types of real access points:. This interface is referred to as the Gi interface. To configure a physical interface to the PDN using Fast Ethernet over the Gi interface Cisco series router platform , use the following commands, beginning in global configuration mode:.
If you enable CEF switching at the global configuration level, then it is automatically enabled for each interface unless it has been specifically disabled at the interface. To configure a real access point on the GGSN, use the following commands, beginning in global configuration mode:. Specifies a name for a new access-point list, or references the name of an existing access-point list, and enters access-point list configuration mode. Note To ensure that CEF switching functions properly, wait a short time before enabling CEF switching after it has been disabled using the no ip cef command.
Be sure that a route exists between the GGSN and the private network that you want to access. You can verify connectivity by using the ping command from the GGSN to the private network address. To configure a route, you can use a static route or a routing protocol.
To configure a static route using VRF, use the following command, beginning in global configuration mode:. On the Cisco series router platform, this interface is physical.
To configure a physical interface to the PDN using Fast Ethernet over the Gi interface, use the following commands, beginning in global configuration mode:. Note The vrf-name argument should match the name of the VRF that you configured using the ip vrf command. After you have completed the prerequisite configuration tasks on the Cisco platform, you can configure access to a VPN with a tunnel or without a tunnel.
The following sections describe the different methods you can use to configure access to a VPN:. To configure access to the VPN in this case, you need to configure the vrf access point configuration command.
For information about the other access point configuration options, see the "Configuring Other Access Point Options" section. Specifies the access point network ID, which is commonly an Internet domain name. The available options are:. Optional Specifies a dynamic address allocation method using IP address pools for the current access point.
This option requires configuration of a local pool using the ip local pool global configuration command. Note If you are using a dynamic address allocation method, then you must configure this command according to the appropriate IP address pool source. When you configure a tunnel, you might consider using loopback interfaces as the tunnel endpoints instead of real interfaces because loopback interfaces are always up.
To configure an IP tunnel to a private network, use the following commands, beginning in global configuration mode:. Specifies the IP address or interface type and port or card number of the Gi interface to the PDN or a loopback interface. Specifies IP address or host name of the private network that you can access from this tunnel.
This section summarizes the configuration options that you can specify for a GGSN access point. Some of these options are used in combination with other global router settings to configure the GGSN.
Further details about configuring several of these options are discussed in other topics in this chapter and other chapters of this book. Note Although the Cisco IOS software allows you to configure other access point options on a virtual access point, only the access-point-name and access-type commands are applicable to a virtual access point.
To configure options for a GGSN access point, use any of the following commands, beginning in access- point list configuration mode:.
Specifies a default authentication, authorization, and accounting AAA server group and assigns the type of AAA services to be supported by the server group for a particular access point on the GGSN, where:. Note The name of the AAA server group that you specify must correspond to a server group that you configure using the aaa group server command. Optional Specifies that a user's session be ended and the user packets discarded when a user attempts unauthorized access to a PDN through an access point.
Note The aggregate auto command will not aggregate routes when using local IP address pools. Note This feature is supported on the Cisco series platform. Note To disable the sending of ICMP messages, ensure that the no ip unreachable interface configuration command has been configured on the virtual template interface. This option requires that a local pool has been configured using the ip local pool global configuration command. The default value is device dependent and is determined by the maximum number of IDBs that can be supported by the router.
The default value is 60 seconds. Note The ppp-regeneration fix-domain and ppp-regeneration verify-domain configurations are exclusive. When ppp-regeneration fix-domain is configured, domain verification cannot be performed.
Note The ppp-regeneration fix-domain and ppp-regeneration verify-domain configurations are mutually exclusive. Optional Specifies the time between 1 and hours that the GGSN waits before purging idle mobile sessions for the current access point. This section describes how to verify that you have successfully configured access points on the GGSN, and includes the following tasks:.
To verify that you have properly configured access points on the GGSN, use the show running-config command and the show gprs access-point commands.
GPRS - PDP Context
The network connects the devices only through GGSN and the mobility of the mobile station is hidden from the rest of the packet data network and from other devices which are connected to network. General Packet Radio Service gprs Tutorial. General Packet Radio Service gprs. All Practice Tests. IT Skills.
GPRS PDP Context - General Packet Radio Service (GPRS)
A packet data network architecture is overlayed or added to the existing GSM architecture to provide the data capability. The existing GSM network architecture is used to carry the circuit switched voice calls as well as the network access, etc. With GPRS providing additional connectivity in terms of packet data, there are naturally a number of upgrades needed to the network architecture required. A number of new elements are needed for the network, but these can operate alongside the existing elements meaning that the GPRS capability is an upgrade to the network and not a completely new network structure. From the diagram given above it can be seen that the GPRS network architecture added some extra elements to the GSM network to enable it to cary the packet data. The PCU added to the base station network routed the data according to whether it was packet or circuit switched. It provides a variety of services to the mobiles:.
Configuring Network Access on the GGSN