# Engineering Rules

This section provides engineering rules or guidelines that must be considered prior to configuring the system for your network deployment.
This appendix describes following engineering rules for HNB-GW service:

- DHCP Service Engineering Rules
- HNB-GW Engineering Rules
- Service Engineering Rules

DHCP Service Engineering Rules

The following engineering rule applies to the DHCP Service:

- Up to 8 DHCP servers may be configured per DHCP service.
- A maximum of 3 DHCP server can be tried for a call.

HNB-GW Engineering Rules

The following engineering rules apply when the system is configured as an HNB-GW:

- A maximum of 16 HNB-GW service can be configured on a system which is further limited to a maximum of 256 services (regardless of type) can be configured per system.
- A maximum of 16 CS-network instances can be configured on system for HNB-GW network function but multiple HNB-GW services can be associated with the same CS-network instance.
- A maximum of 16 PS-network instances can be configured on system for HNB-GW network function but multiple HNB-GW services can be associated with the same PS-network instance.
- A particular HNB-GW service can be associated with more than one CS/PS network entity.
- A maximum of 12 HNB-SCCP-network instance can be configured on system for HNB-GW network function.
- A maximum of 4 HNB-ALCAP service can be configured on system for HNB-GW network function.
- A maximum of 4 Radio Network PLMN ids can be configured in an HNB-GW service.
- A maximum of 4 unique RNC ids can be configured in a Radio Network PLMN.
- A maximum of 1 SeGW IP address can be associated with an HNB-GW service.

Interface and Port Engineering Rules

The rules discussed in this section pertain to both the Ethernet 10/100 and Ethernet 1000 Line Cards and the four-port Quad Gig-E Line Card and the type of interfaces they facilitate.

IuCS Interface Rules

When supporting CS networks, the system can be configured to provide IuCS interface support and connects to the MSC in a CS network in same the PLMN.
The following engineering rules apply to the IuCS interface between the HNB-GW and MSC:

- An IuCS interface is created once the IP address of a logical interface is bound to an ASP-IP defined in the SS7-RD-instance which is defined in SCCP Network instance which is defined in CS Network configuration based on destination point-code.
- The logical interface(s) that will be used to facilitate the IuCS interface(s) must be configured within the egress context.
- CS Network services must be configured within the local context.
- Multiple MSCs (maximum 25) can be configured through IuCS interfaces within the HNB-GW service instance.

IuPS Interface Rules

When supporting PS networks, the system can be configured to provide IuPS interface support and connects to the SGSN in a PS network in the same PLMN.
The following engineering rules apply to the IuPS interface between the HNB-GW and SGSN:

- An IuPS interface is created once the IP address of a logical interface is bound to a PS Network service.
- The logical interface(s) that will be used to facilitate the IuPS interface(s) must be configured within the egress context.
- PS Network services must be configured within the local context at the system level.
- Multiple SGSNs (maximum 25) can be configured through IuPS interfaces within the HNB-GW service instance.

Service Engineering Rules

The following engineering rules apply to services configured within the system:

- A maximum of 256 services (regardless of type) can be configured per system.

CAUTION:

Large numbers of services greatly increase the complexity of management and may impact overall system performance (i.e. resulting from such things as system handoffs). Therefore, it is recommended that a large number of services only be configured if your application absolutely requires it. Please contact your local service representative for more information.