MAINTENANCE SUPPORT
for G3si with Avaya Communication Manager or Avaya Software and SCC or MCC Media Gateways

All major hardware is contained in a multicarrier cabinet (MCC1) that hold up to five carriers or stackable single-carrier cabinets (SCC1s). The solution enables high-speed connections between analog and digital trunks, data lines connected to host computers, data-entry terminals, personal computers, and IP network addresses.

Detailed description
The G3si with Avaya Communication Manager or Avaya Software provides a common architecture platform across all supported line sizes. The Processor Port Network (PPN) is the master controller of the system. The Expansion Port Network (EPN) contains line ports and trunk ports. The universal port hardware allows station circuit packs, trunk circuit packs, and service circuit packs to be installed in any available slot.

G3si with Avaya Communication Manager or Avaya Software provides:

• Scalable applications for messaging, conferencing, collaboration, call centers, mobility, and remote users.
  
• Control of operational costs through the use of networking and management solutions
  
• A simple process for adding features. Add a circuit pack and use the graphical user interface (GUI) to administer it.
  
• Cost-effective and distributed switching arrangements in both LANs and WANs.
  
• Converged network environments through the use of IP and Asynchronous Transfer Mode (ATM) protocols and services
  
• Time Division Multiplex (TDM) transmission and switching infrastructures for both LANs and WANs. TDM supports analog, digital, and IP endpoints, both trunking and station, and an IP interface to a LAN or WAN.
  

Configuration information
The following are main system components:

• Avaya Communication Manager or Avaya Software
  
• A Processor Port Network (PPN) with a Switch Processing Element (SPE) and Port Network (PN)
  
• The 631DA power unit and 631DB power unit for AC power
  
• The 649A power unit for DC power
  
• The Control Carrier
  
• The G3si can use the following Media Gateways:
  
  • SCC1, including power supplies for AC power or DC power
    
  • MCC1, including power supplies for AC power or DC power
    
• Circuit Packs
  
  • The TN2404 processor
    
  • The TN2401 network control and packet interface (NetPkt)
    
  • TN768, TN780, or TN2182 tone clock
    

Processor Port Network and Switch Processing Element
The PPN is a G3si configuration of carriers that contains the following control complex SPE of the system and port interfaces. The control complex consists of three circuit packs:

• The TN2404 RISC processor
  
• The TN2401 Network controller
  
• The TN2182, TN780 or TN768 tone clock board.
  

All of the control circuit packs reside in the control carrier within the PPN. Additional optional circuit packs might be needed such as the TN799DP C-LAN board which provides TCP / IP connectivity and the TN765 Processor Interface for BX.25 connectivity. For high- and critical- reliability systems, the TN792 Duplication Interface pack is used.

When a telephone goes off-hook or signals call initiation, the SPE receives a signal from the port circuit that is connected to the device. The digits of the called number are collected, and the switch is set up to make a connection between the calling device and the called devices.

Port Network

The Port Network (PN) consists of the following components:

• Time Division Multiplexing (TDM) bus: The TDM bus has 484 time slots, 23 B channels, and 1 D channel available per bus. The TDM bus runs internally throughout each PN and terminates on each end. The TDM bus consists of two 8-bit parallel buses, bus A and bus B. Bus A and bus B carry switched digitized voice and data signals and control signals to all port circuits and between port circuits and the SPE. The port circuits place digitized voice signals and data signals on a TDM bus. Bus A and bus B are typically active simultaneously.
  
• Packet bus: The packet bus runs internally throughout each PN and terminates on each end. The packet bus is an 18-bit parallel bus that carries logical links and control messages from the SPE, through port circuits, to endpoints such as terminals and adjuncts. The packet bus carries logical links for both on-switch and off-switch control between some specific port circuits in the system; for example, D-channels, X.25, and remote management terminals.
  
• Port circuits: The port circuits form analog / digital interfaces between the PN and external trunks and devices that provide links between these devices and the TDM bus and packet bus. Incoming analog signals are converted to pulse-code modulated (PCM) digital signals and placed on the TDM bus by port circuits. Port circuits convert outgoing signals from PCM to analog for external analog devices. All port circuits connect to the TDM bus. Only specific ports connect to the packet bus.
  
• Interface circuits: Interface circuits are types of port circuits that reside in the PPN and each EPN. Interface circuits terminate fiber optic cables that connect TDM buses and the packet bus from the PPN cabinet to the TDM bus and packet bus of each EPN cabinet.
  
• An Expansion Interface (EI) circuit pack also terminates:
  
  • Each end of a cable connecting the PPN to an EPN
    
  • Each end of a cable that connects an EPN to another EPN
    
  • The PN end of a cable connected between a PN carrier and an SN carrier.
    
• A Switch Node Interface (SNI) circuit pack terminates the SN carrier end of a cable that is connected between an SN carrier and a PN.
  
• Service circuits connect to an external terminal to monitor, maintain, and troubleshoot the system. Service circuits also provide tone production and detection, call classification, recorded announcements, and speech synthesis.
  

Single-carrier cabinets
Up to three single-carrier cabinets (SCC1s) can be stacked to form a single PN.

Single-carrier cabinets come in any of four configurations:

• A basic control cabinet that contains a TN2404 processor, tone clock, and a power converter
  
• An expansion control cabinet that contains additional port circuit packs, interfaces to the PPN, a maintenance interface, and a power converter
  
• A duplicated control cabinet that contains the same equipment as the basic control cabinet
  
• A port cabinet that contains port circuit packs and a power converter
  

Multicarrier cabinets
A multicarrier cabinet (MCC1) is a 70-in. (178-cm) cabinet that has up to five carriers. See the following figure for an example of an MCC1. The following are the three types of multicarrier cabinets:

• A PPN cabinet that contains the ports, SPE, an interface to an EPN cabinet, and / or a CSS.
  
• An EPN cabinet that contains additional ports, interfaces to the PPN and other EPN cabinets, the maintenance interface, optional interfaces to other EPN cabinets, a switch node (in an SN in a CSS-connected system), or an ATM switch.
  
• An auxiliary cabinet that contains that is equipment used for optional, system-related hardware, such as rack-mounted equipment.
  

Reliability
Duplication is a strategy to create fully redundant systems that are highly reliable. Duplication minimizes single failure points that can interrupt call processing. Three options are available for system reliability and duplication:

• Standard reliability – does not duplicate the tone clocks, the control carrier, or any inter-PN connectivity.
  
• High reliability – duplicates the hardware that is associated with the SPE. The Control Carrier is duplicated, which provides duplicate SPEs and tone clocks. Inter-PN connectivity and EPN tone clocks are not duplicated. The strategy is to duplicate items that are associated with the SPE so that a single fault will not cause the loss of the SPE.
  
• Critical reliability – requires the full duplication of the SPE, inter-PN connectivity, and the tone clocks.
  

As duplication increases, the maximum number of port carriers and port circuit packs per cabinet decreases.