Gb over ip

Gb over IPGb over IPGb over IPGb over IP

Network Operations- Committed for Excellence Gb over IP

Gb over IPGb over IP


GB Over IP:-

Gb over IP offers Internet Protocol (IP) as a transport method in the transmission network. IP can replace Frame Relay (FR) networks as the transport medium in the Subnetwork Service layer. Network Service Control Protocol Data Units (PDU) are incapsulated within the User Datagram Protocol (UDP) datagrams when the IP transport medium is in use.

When IP is used instead of FR, packet based traffic does not go through the circuit based Pulse Code Modulation (PCM) network. IP enables building an efficient transport network for IP based services, and helps to reduce the transmission costs.

Gb over IP is a license-based application software. The license sets a limit to the number of PCUs to which IP NSEs can be configured



The BSC provides Gb interface towards the General Packet Radio Service (GPRS) core network (Serving GPRS Support Node, SGSN). In the BSC, the Gb interface protocol software is implemented in the Packet Control Unit (PCU) plug-in unit, located in each Base Station Controller Signalling Unit (BCSU).

The IP transport can be used in parallel with FR under the same BSC and Base Station Controller Signalling Unit (BCSU). One Network Service Entity (NSE) and each PCU always uses either one, IP or FR transport. Inside one BCSU, separate PCUs can use different transmission media. In the BSC, there is always one local IP endpoint per PCU.

The operator can use the SEG-specific BTS radio network object parameter transport type (TRAT) to select the transport type (IP or FR) of the Network Service Entity Identifier (NSEI) which the BTS/SEG will use.



In Frame Relay, the user builds the Gb interface in two phases: first the Frame Relay bearer channels are created, then the NS layer. In IP, only the NS layer needs to be configured. The BSC then builds the BSSGP virtual connection automatically when the user enables GPRS in a segment.

Packet Control Unit

Packet Control Unit's IP address is configured in the platform. The IP address determines the type of the IP endpoint (IPv4 or IPv6) in NSE and what type of IP packets it can receive. An NSE can only have one type of an IP address.

Network Service Virtual Link (NS-VL)Network Service Virtual Link (NS-VL) is an IP endpoint in SGSN, which is configured in BSC's NSE. From BSC's point of view, SGSN's IP endpoint is called a remote IP endpoint.An IP endpoint (local or remote) is identified by an UDP port and an IP address.The local IP endpoint in PCU may serve several remote IP endpoints inside one NSE. With the IP sub-network, an NS-VL may be established by administrative means (static configuration) or by auto-configuration procedures (dynamic configuration). In dynamic configuration, you can only create one NS-VL per NSE in the BSC. If the SGSN has more IP endpoints in NSE, the BSC will create the remote IP endpoints to the NSE automatically.


Network Service Entity (NSE)

Network Service Entity (NSE) has an end-to-end significance across the Gb interface. The peer NSEs on the BSS side and the SGSN side are identified by the same NSEI value. NSE identifies a group of NS-VLs in the NS layer and a group of BSSGP Virtual Connections (BVCs) in the BSSGP layer.

One NSE per PCU is supported. Within one NSE a maximum of four NS-VLs are supported in PCU1 and sixteen in PCU2.


Benefits of Gb over IP

• Gb over IP reduces transmission costs by using IP capacity instead of frame relay (FR) capacity.

• Gb over IP offers the possibility to use an efficient IP subnetwork for IP based services. • Gb over IP simplifies network management. For example, the restrictions of Frame

Relay do not need to be taken into account anymore. In addition, dynamic IP configuration provides an easy way to configure the IP connection.

Capacity

IP brings more transport capacity into Gb interface. However, Gb over IP licenseneeds to be taken into account, since it can restrict the number of PCUs that canuse Gb over IP.


Restrictions

• Gb over IP requires support from both BSC and SGSN.

• The maximum number of local endpoints is one. The maximum number of remote endpoints is 4 with Packet Control Unit 1 (PCU1), and 16 with PCU2.

• The type of the IP address can be either IPv4 or IPv6 in one NSE.


Requirements for GB Over IP

Software requirements for Gb over IP

Network element Software release required

BSC S11.5 or laterNokia Flexi EDGE BTSs No requirementsNokia UltraSite EDGE BTSs No requirementsNokia MetroSite EDGE BTSs No requirementsNokia 2nd Gen. BTSs No requirementsNokia Talk-family BTSs No requirementsNokia PrimeSite BTSs No requirementsNokia InSite BTSs No requirementsMSC/HLR Not applicableSGSN SG3 or laterNokia NetAct OSS4 or later


Hardware requirements for Gb over IP

Network element Hardware requirements

BSC For BSCi and BSC2i,BSC660TRX an additional LAN panel and new cabling are required for connecting Gb interface to external LAN switch and edge router. BSC3i has LAN connections cabling, switches and panels by default. All BSC PCUs must have Ethernet interface cabling.

BSC3i-1000TRX No requirements

BTS No requirements

TCSM No requirements


Redundancy:-

The PCU is configured into the BCSU unit. According to the N+1 redundancy principle, there is one extra BCSU/PCU unit in the BSC. The additional unit is used only if one of the active units fails.

One logical PCU has two 10/100BaseTx Ethernet interfaces in each PCU board. These allow the connection to the LAN switches (internal in BSC3i; external in BSC2i) that provide the interface for an optimised way of transporting packet switched traffic via IP pipe. The IP traffic runs through one Gb over IP interface; the other interface is used only for redundancy purpose if the active interface fails.

With Gb interface over IP, both LAN interfaces (0 and 1) can be used

The LAN interface's duplex speed is fixed to auto negotiation mode.


GB Over IP creation in BSC:-

Step 1:- Disable the GENA & EGENA for the BTSs.

Step 2:- Delete the NSVCIs and Bearer channels

Step 3:- Check that the license covering GB over IP has been installed (W7I). ZW7I: LIC, FULL: LIC=<license code>:;

Step 4:- Check the GB over IP feature state (W7I). ZW7I: FEA, FULL: FEA=7;

Step 5:- Assign the IP address for PCU in all the BCSUs with (ZQRN) ZQRN :< unit type>,<unit index>:<plug-in unit type>,<plug-in unit

index>:<interface name>:<ip address>,<L/P>,<DEL>:<net mask length>:<state>:<mtu>;

Step 6:- Create Default Gateway for all the PCUs with (ZQKC) ZQKC:<unit type>,<unit index>:<plug-in unit type>, <plug-in unit index>:<destination IP address>, <netmask length>:<gateway IP address>:<route type>;


Step 7:- Create Packet Service Entity (PSEI) with (ZFXA) ZFXA:PSEI=<packet service entity identifier>,

BCSU=<base station controller signaling unit>, PCU=<packet control unit>;

Step 8:- Create the network service virtual link (NS-VL) with (ZFXK) ZFXK:NSVLI=<network service virtual link identifier>,NAME=<network service virtual link name>,NSEI=<network service entity identifier>,PSEI=<packet service entity identifier>: LPNBR=<local UDP port number>,PRE=Y:RIP=<remote IP address>,RPNBR=<remote UDP port number>;

Step 9:- Check the creation and state of the NS-VL (FXI) ZFXI:NSVLI=<network service virtual link identifier>;


Example:-

1. Check the License feature in BSC ZW7I:FEA,FULL:FEA=7;

2. Assign the IP address for PCU ZQRN:BCSU,0:PCUS,1:IFETH0:131.230.42.22,L;

3. Assign the Default Gateway for PCU ZQKC:BCSU,0:PCUS,1::131.230.42.2;

4. Check the IP address assignment ZQRI:BCSU,0:PCUS,1;

5. Creation of PSEI ZFXA:PSEI=24,BCSU=0,PCU=1;


6. Creation of NSVLI ZFXK:NSVLI=2,NAME=MAIN_CH_02,NSEI=1,PSEI=24: LPNBR=50000,PRE=N:RIP=”192.168.0.2”,RPNBR=50000,RDW=1, RSW=1;

7. Check the States of NSVLI ZFXI:NSVLI=2;


Engineering

Gb over ip