13.2.1  

PRI 
 

Introduction  
The HiPath 3800, HiPath 3500, HiPath 3550 and systems can be configured to support Primary Rate services from the public network. A primary rate interface (PRI) consists of 23 bearer (B) channels and 1 data (D) channel. Each channel supports 64 Kbps of bandwidth.
HiPath 3550The HiPath 3500 and support one T1 interface (TST1 module) that can be configured as a primary rate interface. A CSU is required for each interface connected to the public network. HiPath 3550The HiPath 3500 and support a maximum of one CBC group. The group can also be configured with a maximum of eight CBC trunk groups. Typically, the entire T1 span is placed in a single trunk group, but depending on the application, the primary rate channels can be separated into discrete route groups. This may be required for applications where a portion of the channels can be separated out for non-system data applications.
A span or spans must be selected as the reference interface for the Central Office. A hierarchical table is provided for assigning four reference-clock points. If the primary clock source fails, the next clock source specified is used as the reference. When the primary clock source returns, the system automatically resynchronizes to this clock. A maximum of four reference clocks can be defined per system.

Model-Specific Data  

 Subject  
 HiPath 3800  
 HiPath 3550  
 HiPath 3500  
 HiPath 3350  
 HiPath 3300  
Feature available in  
 x  
 x  
 -  
Hardware requirements  
 DIU2U, DIUT2  
 TST1  
 -  
Number of T1 modules per system  
 5  
 1  
 -  
Number of CBC groups per system  
 4  
 1  
 -  
Number of trunk groups per CBC group  
 8  
 8  
 -  
Software requirements  
 V5.0 or later  
 V1.0 or later  
 -  
Depending on the PRI provider's requirements, users need to configure some or all of the following for PRI setup:
 •   Signal, protocol, and emulation type
 •   Frame/line/encoding
 •   B channel allocation mode and identifier
 •   Number of B channels
 •   Trunk group calling service
For networking with PRI, customers can use either tie trunks or the public-switched telephone network.
Protocol type allows customers to select the interface between the HiPath 3800, HiPath 3500, HiPath 3550 and the PRI provider. Protocols are different for local exchange carriers (LECs) and for inter-exchange carriers (IECs). Customers might prefer an IEC, for example, if they want to place calls on a tie trunk using station numbers without going through the local exchange.
Customers can choose a different carrier and protocol for each PRI span. The HiPath 3000 systems support seven commonly used LEC protocols and seven commonly used IEC protocols. Table 13-1 and Table 13-2 show the protocols available for each slot.

LEC Protocols  

 Table 13-1   Supported LEC Protocols
 LEC Carrier  
 Switch  
 Protocol  
AT&T  
5ESS  
Custom  
AT&T  
5ESS  
NI-2  
Bell Canada  
DMS100  
Custom  
GTE  
GTT5  
NI-2  
Nortel  
DMS100  
Custom  
Siemens  
EWSD  
Custom  
Siemens  
EWSD  
NI-2  

IEC Protocols  

 Table 13-2   Supported IEC Protocols
 IEC Carrier  
 Switch  
 Protocol  
AT&T  
4ESS  
Custom  
MCI  
DMS250  
AT&T 4ESS emulation  
MCI  
DEX600  
AT&T 4ESS emulation  
Sprint  
DMS250  
AT&T 4ESS emulation  
Westinghouse  
DMS250  
AT&T 4ESS emulation  
GSA  
DMS250  
DMS250  
GSA FTS 2000  
5ESS  
5ESS  
Emulation type is determined by the protocol. Users need to select the emulation type that matches the ISDN service they have ordered: Super Frame (SF) or Extended Super Frame (ESF).
The data format for SF emulation is inverted high-level data link control (HDLC); the data format for ESF is normal HDLC.
Frame/line/encoding allows customers to select the type of encoding used on the D channel. The choices are normal or inverted. Normal is the default. The type of frame and line encoding depends on the protocol. HiPath 3550 and HiPath 3500 automatically set the correct type of frame and line encoding according to the protocol.
B channel allocation mode and identifier allows customers to select the system method of finding an available B channel when needed. The choices are high and low. High begins searching at the highest-numbered B channel of the highest-numbered T1 span in the PRI trunk group and continues in descending order. Low begins searching at the lowest-numbered B channel of the lowest-numbered T1 span in the PRI trunk group and continues in ascending order.
Select the opposite mode from that used by the CO; this will avoid collisions when both the CO and the HiPath 3000 are trying to seize a channel.
Number of B channels allows users to enter the number of B channels for the system, so that the system knows where to begin searching for channels to allocate. The number entered here depends on the number of B channels that the customer has ordered.
Trunk group calling service allows users to select the type of service for each trunk group. The HiPath 3550, HiPath 3350, HiPath 3500and HiPath 3300 support 36 types of trunk group service. Customers select the type of service according to the service ordered from the ISDN provider.
If you are unsure the trunk group calling service, consult the ISDN provider for more information.  
The following tables outline the voice and data services available through the public network providers in the North American market.

 Table 13-3   Inter-Exchange (IEC) Protocol Calling Services
   
 ATT 4ESS  
 MCI DMS250/MCI
DEX600  
 SPRINT
DMS250  
 Westing.
DMS250  
 FTS2000
DMS/5ESS  
 In-WATS (800)  
Megacom 800-TFM  
MCI 800  
ULTRA 800  
WICN-InWATS  
N/A  
 Out-WATS  
Megacom  
MCI Prism-WATS  
SPR Ultra WATS  
WICN-OutWATS  
N/A  
 In-WATS (900)  
Multiquest  
MC!/900  
N/A  
N/A  
N/A  
 Intl IN-WATS  
Inter-800  
MCI 800  
N/A  
N/A  
N/A  
 PVN  
AT&T SDDN  
MCI VN-VS  
SPRINT-VPN  
N/A  
N/A  
 Intl VPN  
AT&T SDN-GSDN  
N/A  
SPRINT-VPN  
N/A  
N/A  
 SDS 56  
Accu-SDS  
No  
Accu-SDS  
Accu-SDS  
N/A  
 SDS 94-c/r  
Accu-SDS  
No  
Accu-SDS  
Accu-SDS  
N/A  

 Table 13-4   Local Exchange (LEC) Protocol Calling Services
   
 AT&T
5ESS/  
 Siemens EWSD  
 Nortel
DMS100  
 Bell Cnd
DMS100  
 Generic NI2  
 Siemens NI2  
 AT&T 5ESS NI2  
In-WATS (800)  
Megacom  
DMS100 InWATS  
NI2 InWATS  
Out-WATS  
Megacom  
DMS100 OutWATS  
NI2 OutWATS  
In WATS (900)  
N/A  
N/A  
N/A  
Intl InWATS (800)  
N/A  
N/A  
N/A  
PVN  
N/A  
DMS100 PV  
N/A  
Multiband OutWATS  
Megacom  
DMS100 OutWATS  
NI2 OutWATS  
Access to LEC operator  
No  
No  
No  
Access to default IEC operator  
No  
No  
No  
Equal access to IEC Long Distance services  
Megacom  
DMS100 OutWATS  
NI2 OutWATS  
Basic CO access  
No  
No  
No  
Access to IEC operator  
No  
No  
No  
SDS-56  
No  
No  
No  
SDS-64 c/r  
No  
No  
No