1.26 Networking Features

1.26.1 TIE Line Service

1.26.1.1 TIE Line Service–OVERVIEW

Description

Two PBXs can be connected by a privately leased telephone line, and calls can be made between PBXs using this "TIE line". TIE lines provide a cost-effective way to route calls and communications, and are often used to connect corporate offices located in different cities. When two or more PBXs are connected by TIE lines, they can create a "private network" which is independent of the public network (i.e., the telephone company and its lines). Calls can be handled between extensions of the PBXs without using the services of a telephone company, even though the PBXs may be installed in different locations. TIE lines can also be used in conjunction with CO lines. This allows an outside caller to call one PBX and be connected to an extension in a different PBX, or allows an extension user to make a call to an outside party which is routed first through another PBX in the private network. Routing calls this way can be very cost-effective. For example, an employee in Los Angeles can make a call to a customer in New York by routing the call through the PBX in the company's New York office. In such a case the call will be billed to the New York office as a local call. In order to make and receive calls using TIE lines, various tables must be programmed to instruct each PBX on how to direct and receive calls that are made using TIE line service.

1.	Interface
	A private network can be established using the following methods. Method Port (Channel) Type* Available Services Network Specification Details In T1 Line TIE (E&M) • TIE Line Service Digital (64 kbps × 24 channels) – PRI Line QSIG (Master or Slave) • TIE Line Service • QSIG Services Digital (ISDN 23B+D) • 1.26.2 QSIG Network VoIP Not assignable • TIE Line Service • QSIG Services • IP data send/receive Internet Protocol (IP) • 1.26.3 Voice over Internet Protocol (VoIP) Network * In order to establish a private network, port (channel) type must be assigned through system programming as shown.
2.	Types of Calls That Can be Made Using TIE Lines
	TIE Line Calls Calls can be made between extensions of different PBXs connected by a TIE line. These PBXs may be connected to each other directly, or through another PBX. To make a TIE line call, an extension user will either need to dial an extension number, or a PBX code in addition to an extension number, depending on the method used to identify different PBXs on the private network. (See, "4. Identifying PBXs and their Extensions", below.) TIE Line with CO Line Calls TIE line calls can be made to or from parties that are outside the private network. There are three ways in which TIE lines can connect with CO lines. First, outside callers can call one PBX and then be connected to an extension of another PBX (CO-to-TIE Line Calls). Secondly, an extension user at one PBX can make a CO line call by using a CO line connected to another PBX in the private network (TIE-to-CO Line Calls). Finally, an outside caller can call one PBX and then be connected to another outside party after the call is first routed through another PBX (CO-to-TIE-to-CO Line Calls).
3.	Routing Calls via TIE Lines
	Normally to make a telephone call, a person dials a number and the call is connected. What happens between the dialing of the number and the ringing on the other end is usually never considered, because telephone companies handle all the routing for us. To make or receive calls using TIE lines however, the PBXs must be programmed so they will know how to handle those calls as they are received and sent. In situations where only two PBXs connected by one TIE line make up the private network, this programming is straightforward. In situations where multiple PBXs are connected by several TIE lines however, programming is more complex. No matter what kind of private network you use, careful programming will allow PBX users to make calls easily and also route calls in a way that is most cost-effective or efficient for your company or organization. [Examples of Private Networks] Example Network 1 Two PBXs connected by one TIE line. Example Network 2 Three PBXs connected by two TIE lines. PBX-2 is connected to both TIE lines. This PBX links the other two PBXs, and passes calls from one PBX to the other. PBX-2 must be programmed to send calls to PBX-1 via one TIE line, and calls to PBX-3 via another TIE line. This programming will also allow PBX-2 to receive and send calls made between PBX-1 and PBX-3. Example Network 3 Three PBXs connected by three TIE lines. Each PBX is connected to two TIE lines, and must be programmed to send calls to each PBX via the preferred TIE line, however, if the TIE line directly connecting two PBXs (PBX-1 and 2, for example) is busy, calls between these PBXs can be routed circularly through other PBXs (PBX-1 PBX-3 PBX-2). Example Network 4 Four PBXs connected by four TIE lines. Each PBX is connected to two TIE lines, and must be programmed to send calls to each PBX via the preferred TIE line. Calls between PBXs that are not directly connected must be routed through another PBX. Also, if the TIE line directly connecting two PBXs is busy, calls between these PBXs can be routed circularly through other PBXs. For example, a call from PBX-1 to PBX-4 can be routed as follows: PBX-1 PBX-2 PBX-3 PBX-4. Example Network 5 Four PBXs connected to each other by four TIE lines. Each PBX is connected to the public network via CO lines. It is possible for any PBX extension to call an outside party by routing a call via TIE line to another PBX, then to the public network.
4.	Identifying PBXs and their Extensions
	When PBXs are connected to each other to form a private network, there must be some way to distinguish the PBXs from each other so that calls can be sent to the intended destination of the desired PBX. This can be done either by identifying each PBX specifically, or by making each extension number in the private network unique. Each PBX on a private network must be programmed to use the same method to identify itself, explained below. a) PBX Code Method (Access with PBX Code) PBXs can be distinguished from each other on a private network by assigning a PBX code to each one. These codes are used by the PBXs to determine how to route calls to other PBXs, and also let a PBX know when it receives a call that it should handle itself. If a call does not contain a PBX code, the call will not be handled correctly. PBX codes also allow the same extension numbers to be used on different PBXs. ( 1.26.1.2 PBX Code Method (Access with PBX Code)) b) Extension Number Method (Access without PBX Code) PBXs can also be distinguished by the extension numbers they use. With this method, the extension number is all that is needed for a PBX to determine how to route calls to other PBXs; no PBX code is necessary. While this method allows extensions in other PBXs to be called easily–there are fewer numbers to dial–the number of extension numbers which can be used throughout the private network will be limited. ( 1.26.1.3 Extension Number Method (Access without PBX Code))
5.	TIE Line Routing Flowcharts
	[Making a Call via a TIE Line from an Extension]   [Receiving a Call via a TIE Line]

1.26.1.2 PBX Code Method (Access with PBX Code)

Description

PBXs on a private network can be distinguished from each other by assigning a PBX code to each one. When a PBX makes or receives a TIE line call that contains a PBX code, it can recognize right away if it should handle the call itself or pass it on to another PBX. If each PBX on a private network has a PBX code, the extension numbers used in one PBX can also be used again in another PBX. If a PBX is assigned a PBX code, it will look for PBX codes when receiving calls on TIE lines; if a call does not contain a PBX code, it will not be handled correctly. Using PBX codes to make or receive calls via a TIE line is called "PBX Code Method (Access with PBX Code)".

1.	Programming for PBX Code Method (Access with PBX Code)
	Each PBX in the private network will refer to some or all of following tables when making and receiving calls via TIE line using PBX Code Method (Access with PBX Code). TIE Line Routing and Modification Table This table is used when a PBX makes a call to another PBX, or passes a received call on to another PBX. It contains leading numbers as well as routing instructions for each leading number; it controls which calls are sent on which TIE lines. Use this table to store the PBX codes of other PBXs on the network, the lines which can be used when sending calls to each PBX, and, if necessary, a method to modify dialed numbers before sending them down the TIE line. When a PBX is about to send a number down a TIE line, it checks the number and finds the preprogrammed leading digits (PBX code) of that number in this table. It then checks the highest-priority (most preferred) CO line group assigned to that leading number. When it finds a line within the highest-priority CO line group that is available, it modifies the number as programmed in this table. This modification allows an identifying number or code to be attached to the beginning of calls made to certain PBXs, so that the receiving PBX will be able to handle the call properly. After modification, the number is sent down the line. Incoming Number Modification Table This table is referred to when a call is received on a TIE line. When a PBX receives a call on a TIE line, it searches the Incoming Number Modification Table for instructions on how to modify the received telephone number depending on which CO line the call was received. Next the PBX will look for its own PBX code at the beginning of the modified number and try to handle the call by itself, by sending the call to one of its own extensions, for example. If it does not find its own PBX code, it refers to the TIE line Routing and Modification Table in order to send the call down the TIE line. Own PBX Code This information is used to determine whether or not an incoming TIE line call is meant for the PBX receiving the call. If a PBX has been assigned a PBX code, it will look for its code at the beginning of all calls received via TIE line. If it finds its own code, it will handle that call by itself. If it does not find its code, it refers to the TIE Line Routing and Modification Table in order to pass the call to another PBX. Note that PBX codes should not be assigned if the Extension Number Method (Access without PBX Code) is the preferred method for handling calls on the private network. ( 1.26.1.3 Extension Number Method (Access without PBX Code))
2.	Making and Receiving TIE Line Calls
	To make a call to an extension of another PBX, an extension user dials the TIE Line Access number, PBX code, and an extension number. [Example] [Programming Example: TIE Line Routing and Modification Table for PBX-1] Explanation: PBX-1 makes a call. Extension 1001 of PBX-1 dials the TIE Line Access number "7", the PBX code "903", and an extension number "1001".
	1. The TIE Line Access number was dialed, therefore PBX-1 checks its TIE Line Routing and Modification Table. Finds leading number "903". 1st priority CO line group is "2". 2. No lines are available in this CO line group. The PBX checks for an available line in the 2nd priority CO line group (CO line group 1), and finds an available line. No modification is programmed. 3. PBX-1 removes the TIE Line Access number and sends the remaining digits down the TIE line via CO line group 1. The number is now "903-1001".
	PBX-2 receives the call.
	1. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "903-1001". 2. PBX-2 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "903". 1st priority CO line group is "8". No modification is programmed. 3. Sends the call down the TIE line via CO line group 8. The number is still "903-1001".
	PBX-3 receives the call.
	1. PBX-3 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "903-1001". 2. PBX-3 recognizes its own PBX code and sends the call to extension 1001.
3.	TIE Line with CO Line Calls
	Three types of CO line calls can be made or received via TIE lines: 1) CO-to-TIE Line Calls 2) TIE-to-CO Line Calls 3) CO-to-TIE-to-CO Line Calls
	3.1. CO-to-TIE Line Calls A CO line call can be redirected to a destination of another PBX via Call Forwarding (FWD), Intercept Routing, or Call Transfer. [Example] Explanation: An outside caller dials "555-0000". 1. The call is received by PBX-1 and directed to extension 1001, which is assigned (not shown here) as the Direct Inward Dialing (DID) destination for the DID number "555-0000", in the DID Table of PBX-1. ( 1.1.1.3 Direct Inward Dialing (DID)) 2. Calls directed to extension 1001 of PBX-1 are redirected to extension 2001 of PBX-2 because of one of the following: a) Extension 2001 of PBX-2 is programmed (not shown here) as the FWD or Intercept Routing destination for calls to extension 1001 of PBX-1. The destination is programmed as [TIE Line Access number] + [PBX code of PBX-2] + extension number "2001". b) The extension 1001 user transferred the call to extension 2001 of PBX-2 by dialing the TIE Line Access number "7", the PBX code of PBX-2 "902", and the extension number "2001". 3.2. TIE-to-CO Line Calls An extension user can make a CO line call by first routing the call through another PBX. These calls can be routed by Automatic Route Selection (ARS), or restricted based on the Class of Service (COS) of the CO line group carrying the call. a) TIE-to-CO Line Calls [Example] Explanation: PBX-1 makes a call. Extension 1001 dials the TIE Line Access number "7", the PBX code of PBX-2 "902", and the Idle Line Access number of PBX-2 "9", followed by the telephone number "1-212-555-1234". 1. The TIE Line Access number was dialed, therefore PBX-1 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "902". No modification is programmed. 2. PBX-1 removes the TIE Line Access number and sends the remaining digits down the TIE line. The number is now "902-9-12125551234". PBX-2 receives the call. 1. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. PBX-2 removes its PBX code "902". The number is now "9-12125551234". 2. PBX-2 recognizes its Idle Line Access number, "9", and sends the remaining number, "12125551234", to the telephone company using an idle CO line. b) TIE-to-CO Line Calls Routed by ARS ARS can be used to route calls through other PBXs. This allows PBX users to dial telephone numbers as they normally would (i.e., by dialing the Idle Line Access number "9" then the telephone number) without having to think about which calls will be routed through another PBX via TIE line, and which calls will be sent to a CO line connecting their PBX to the telephone company. [Example] Explanation: Extension 1001 dials the Idle Line Access number of PBX-1 "9", followed by the telephone number "1-212-555-1234". 1. The Idle Line Access number "9" was dialed, therefore PBX-1 modifies the dialed number via its ARS programming (not shown here). It removes the Idle Line Access number, adds the PBX code and Idle Line Access number of PBX-2 "902-9", and sends the number down the TIE line to PBX-2. The number is now "902-9-12125551234". 2. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. PBX-2 removes its PBX code (902). The number is now "9-12125551234". 3. PBX-2 recognizes its Idle Line Access number, "9", and sends the remaining number, "12125551234", to the telephone company using an idle CO line. c) Blocking TIE-to-CO Line Calls TIE-to-CO line calls can be prohibited based on the telephone number of the outside party that the extension user is trying to make a call to, or can be blocked completely based on the CO line group carrying the outgoing call. When making TIE-to-CO line calls, the incoming TIE line call is received by one CO line of a PBX, and the outgoing CO line call is made using another CO line. Both lines belong to CO line groups, and both groups have a Class of Service (COS), therefore, Toll Restriction (TRS) can be used to allow certain TIE-to-CO line calls to be made while others are prohibited. ( 1.8.1 Toll Restriction (TRS)) These restrictions are based on the COS of the CO line group carrying the incoming TIE line call. Additionally, the outgoing CO line group can be programmed to completely block all calls from being made when incoming TIE line calls are received on CO line groups of a certain COS. (External Call Block) Note that it is possible for a PBX user to bypass these restrictions by using Direct Inward System Access (DISA). By making a TIE line call to a floating extension number used by the DISA feature of the other PBX, then using Walking COS ( 1.8.4 Walking COS) or Verified Code Entry ( 1.8.5 Verified Code Entry) through DISA, a PBX user can make a call that is normally restricted, provided his or her COS is authorized to make the call. [Programming Example: CO Line Group COS, PBX-2] [Programming Example: External Call Block, PBX-2] [Example of TIE-to-CO Line Call, Blocked/Restricted Based on COS] Explanations: TIE-to-CO Line Call Blocked by External Call Block Extension 1001 dials a number to make a TIE-to-CO line call. 1. The call is received at PBX-2 on CO line group 1, which has a COS of 3. 2. According to the TIE Line Routing and Modification Table of PBX-2 (not shown here), the CO line call should be made using CO line group 3, however, this CO line group is set to block COS 3 calls. TIE-to-CO Line Call Restricted by TRS Extension 1001 dials a number to make a TIE-to-CO line call. 1. The call is received at PBX-2 on CO line group 1, which has a COS of 3. 2. TRS programming for PBX-2 (not shown here) prohibits the call from being made based on the COS of CO line group 1. [Example of Bypassing TIE-to-CO Line Call Restrictions] Explanations: PBX-1 makes a call. Extension 1001 dials the TIE line access number of PBX-1 "7", the PBX code of PBX-2 "902", followed by a DISA floating extension number of PBX-2. 1. The TIE Line Access number was dialed, therefore PBX-1 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "902". No modification is programmed. 2. PBX-1 removes the TIE Line Access number and sends the remaining digits down the TIE line. The number is now "902" plus the DISA floating extension number of PBX-2. PBX-2 receives the call. 1. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. 2. PBX-2 recognizes its own PBX code and sends the call to its DISA feature. From this point, if the COS assigned to the caller's extension or verified code allows, the caller can use Walking COS or Verified Code Entry to bypass the restrictions and make a CO line call. d) TIE Line Call Routed to CO Line via FWD/Intercept Routing/Call Transfer A TIE line call can be redirected to an outside party via FWD, Intercept Routing, or Call Transfer. [Example] Explanation: PBX-1 makes a call. Extension 1001 of PBX-1 dials the TIE Line Access number "7", the PBX code "902", and an extension number "1001". 1. The TIE Line Access number was dialed, therefore PBX-1 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "902". 1st priority CO line group is "1". No modification is programmed. 2. PBX-1 removes the TIE Line Access number and sends the remaining digits down the TIE line via CO line group 1. The number is now "902-1001". PBX-2 receives the call. 1. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "902-1001". 2. PBX-2 removes its own PBX code "902" and sends the call to extension 1001. 3. Calls directed to extension 1001 are redirected to the outside party (1-212-555-1234) because of one of the following: a) This number is programmed (not shown here) as the FWD or Intercept Routing destination for calls to extension 1001. The destination is programmed as "9-12125551234". b) The extension 1001 user transferred the call to the outside party by dialing "9-12125551234". 3.3. CO-to-TIE-to-CO Line Calls An incoming CO line call can be routed to the DISA feature of a PBX, then the caller can make a CO line call which is routed via ARS through another PBX. [Example] Explanation: The outside caller dials a telephone number which is routed to the DISA feature of PBX-1, then dials the Idle Line Access number of PBX-1 "9", followed by the desired outside party's telephone number (1-212-555-1234). 1. The Idle Line Access number "9" was dialed, therefore PBX-1 modifies the dialed number via its ARS programming (not shown here). It removes the first digit "9", adds the PBX code and Idle Line Access number of PBX-2 "902-9", and sends the number down the TIE line to PBX-2. The number is now "902-9-12125551234". 2. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. PBX-2 removes its PBX code (902). The number is now "9-12125551234". 3. PBX-2 recognizes its Idle Line Access number, "9", and sends the remaining number, "12125551234", to the telephone company using an idle CO line.

Conditions

•	When a TIE line call arrives at an extension, it is treated as a CO line call, not as an intercom call. If the called extension is busy and has disabled Call Waiting, the caller will hear a busy tone or be redirected to the Intercept Routing–Busy destination, if one is programmed. If the called extension has set Do Not Disturb (DND), the call will be redirected to the Intercept Routing–DND destination, if one is programmed. ( 1.1.1.5 Intercept Routing)
•	The amount of time the PBX waits for a digit to be dialed before sending a reorder tone can be specified through system programming (TIE Receiving Dial Inter-digit time).
•	Throughout the examples in this section, the CO Line Group Access number "8" and a CO line group number ("02", for example) can be dialed instead of the TIE Line Access number "7" if the caller wishes to select a specific CO line group with which to make a call. Note, however, that if the TIE Line Access number is not dialed, the PBX will not check the TIE Line Routing and Modification Table for instructions on how to modify the dialed number before sending it down the TIE line using the specified CO line group.

Feature Guide References

User Manual References

1.26.1.3 Extension Number Method (Access without PBX Code)

Description

PBXs can be distinguished from each other on a private network by the extension numbers they use. When a PBX makes or receives a TIE line call that contains an extension number, it can recognize right away if it should handle the call itself, or pass it on to another PBX. If each extension on a private network has a unique number, calling extensions in other PBXs can be greatly simplified. Making or receiving calls via TIE line between PBXs that rely on unique extension numbers to distinguish themselves is called "Extension Number Method (Access without PBX Code)".

1.	Programming for Extension Number Method (Access without PBX Code)
	Each PBX in the private network will refer to some or all of following tables when making and receiving calls via TIE line using Extension Number Method (Access without PBX Code). TIE Line Routing and Modification Table This table is used when a PBX makes a call to another PBX, or passes a received call on to another PBX. It contains leading numbers as well as routing instructions for each leading number; it controls which calls are sent on which TIE lines. Use this table to store the first few digits (leading digits) of the extension numbers used by other PBXs on the private network, the lines which can be used when sending calls to each PBX, and, if necessary, a method to modify dialed numbers before sending them down the TIE line. When a PBX is about to send a number down a TIE line, it checks the number and finds the preprogrammed leading digits of that number in this table. It then checks the highest-priority (most preferred) CO line group assigned to that leading number. When it finds a line within the highest-priority CO line group that is available, it modifies the number as if programmed to do so. After modification, the number is sent down the line. Incoming Number Modification Table This table is referred to when a call is received on a TIE line. When a PBX receives a call on a TIE line, it searches the Incoming Number Modification Table for instructions on how to modify the received telephone number depending on which CO line the call was received. After modifying the number, the PBX will check to see if this modified number is stored in its Extension Numbering Plan or Other PBX Extension list (see "Flexible Numbering" below). If the PBX cannot handle the call itself (when a call is meant for an extension of a different PBX, for example), it refers to the TIE Line Routing and Modification Table in order to send the call down the TIE line. Flexible Numbering Flexible Numbering contains several numbering plans which will be referred to after an extension user dials a number, or after an incoming TIE line call is modified by the Incoming Number Modification Table. If the dialed number or modified number is found in the Extension Numbering Plan or Feature Numbering Plan, the PBX will send the call to one of its own extensions or access the appropriate feature, respectively. If the modified number is found in the Other PBX Extension list, the PBX will check the TIE Line Routing and Modification Table for instructions on how to send the call down the TIE line.
2.	Making and Receiving TIE Line Calls
	To make a call to an extension of another PBX, an extension user simply dials an extension number. [Example] [Programming Example: TIE Line Routing and Modification Table for PBX-1] Explanation: PBX-1 makes a call. Extension 1001 of PBX-1 dials "3001".
	1. PBX-1 checks its Extension Numbering Plan. "3001" is not one of its extensions. 2. PBX-1 checks its Other PBX Extension list, and finds an extension "3001". 3. PBX-1 checks its TIE Line Routing and Modification Table. Finds leading number "3". 1st priority CO line group is "2". 4. No lines are available in this CO line group. The PBX checks for an available line in the 2nd priority CO line group (CO line group 1), and finds an available line. No modification is programmed. 5. Sends the call down the TIE line via CO line group 1.
	PBX-2 receives the call.
	1. PBX-2 checks its Incoming Number Modification Table. No modification is programmed. The number is still "3001". 2. PBX-2 checks its Extension Numbering Plan. "3001" is not one of its extensions. 3. PBX-2 checks its Other PBX Extension list, and finds an extension "3001". 4. PBX-2 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "3". 1st priority CO line group is "8". No modification is programmed. 5. Sends the call down the TIE line via CO line group 8. The number is still "3001".
	PBX-3 receives the call.
	1. PBX-3 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "3001". 2. PBX-3 checks its Extension Numbering Plan. "3001" is one of its extensions. 3. PBX-3 sends the call to extension 3001.
3.	TIE Line with CO Line Calls
	Three types of CO line calls can be made or received via TIE lines: 1) CO-to-TIE Line Calls 2) TIE-to-CO Line Calls 3) CO-to-TIE-to-CO Line Calls
	3.1. CO-to-TIE Line Calls An extension of a PBX can be the destination of a CO line call received by another PBX first. a) Incoming CO Line Call Destination Assignment An extension of a PBX can be the Direct In Line (DIL) or Direct Inward Dialing (DID) destination of a CO line call received first by another PBX. [Example] Explanation: An outside caller dials "555-0000". The call is received by PBX-1 and directed to extension 2001, which is assigned (not shown here) as the DID destination for the DID number "555-0000", in the DID Table of PBX-1. b) FWD/Call Transfer/Intercept Routing to the TIE Line A CO line call can be redirected to a destination of another PBX via Call Forwarding (FWD), Intercept Routing, or Call Transfer. [Example] Explanation: An outside caller dials "555-0000". 1. The call is received by PBX-1 and directed to extension 1001, which is assigned (not shown here) as the DID destination for the DID number "555-0000" in the DID Table of PBX-1. 2. Calls directed to extension 1001 are redirected to extension 2001 because of one of the following: a) Extension 2001 is programmed (not shown here) as the FWD or Intercept Routing destination for calls to extension 1001. The destination is programmed as "2001". b) The extension 1001 user transferred the call to extension 2001 by pressing the Transfer button and dialing "2001". 3.2. TIE-to-CO Line Calls An extension user can make a CO line call by first routing the call through another PBX. These calls can be routed by Automatic Route Selection (ARS), or restricted based on the Class of Service (COS) of the CO line group carrying the call. a) TIE-to-CO Line Calls [Example] Explanation: PBX-1 makes a call. Extension 1001 dials the TIE Line Access number "7" and the Idle Line Access number of PBX-2 "9", followed by the telephone number "1-212-555-1234". 1. The TIE Line Access number was dialed, therefore PBX-1 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "9". No modification is programmed. 2. PBX-1 removes the TIE Line Access number and sends the remaining digits down the TIE line. The number is now "9-12125551234". PBX-2 receives the call. 1. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "9-12125551234". 2. PBX-2 recognizes its Idle Line Access number, "9", and sends the remaining number, "12125551234", to the telephone company using an idle CO line. b) TIE-to-CO Line Calls Routed by ARS ARS can be used to route calls through other PBXs. This allows PBX users to dial telephone numbers as they normally would (i.e., by dialing the Idle Line Access number "9" then the telephone number) without having to think about which calls will be routed through another PBX via TIE line, and which calls will be sent to a CO line connecting their PBX to the telephone company. [Example] Explanation: Extension 1001 dials the Idle Line Access number of PBX-1 "9", followed by the telephone number "1-212-555-1234". 1. The Idle Line Access number "9" was dialed, therefore PBX-1 modifies the dialed number via its ARS programming (not shown here). It removes the first digit "9", adds the Idle Line Access number of PBX-2 "9", and sends the number down the TIE line to PBX-2. The number is now "9-12125551234". 2. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "9-12125551234". 3. PBX-2 recognizes its Idle Line Access number "9", so it sends the call to the outside party "1-212-555-1234". c) Blocking TIE-to-CO Line Calls TIE-to-CO line calls can be prohibited based on the telephone number of the outside party that the extension user is trying to make a call to, or can be blocked completely based on the CO line group carrying the outgoing call. When making TIE-to-CO line calls, the incoming TIE line call is received by one CO line of a PBX, and the outgoing CO line call is made using another CO line. Both lines belong to CO line groups, and both groups have a Class of Service (COS), therefore, Toll Restriction (TRS) can be used to allow certain TIE-to-CO line calls to be made while others are prohibited. ( 1.8.1 Toll Restriction (TRS)) These restrictions are based on the COS of the CO line group carrying the incoming TIE line call. Additionally, the outgoing CO line group can be programmed to completely block all calls from being made when incoming TIE line calls are received on CO line groups of a certain COS. (External Call Block) Note that it is possible for a PBX user to bypass these restrictions by using Direct Inward System Access (DISA). By making a TIE line call to a floating extension number used by the DISA feature of the other PBX, then using Walking COS ( 1.8.4 Walking COS) or Verified Code Entry ( 1.8.5 Verified Code Entry) through DISA, a PBX user can make a call that is normally restricted, provided his or her COS is authorized to make the call. [Programming Example: CO Line Group COS, PBX-2] [Programming Example: External Call Block, PBX-2] [Example of TIE-to-CO Line Call, Blocked/Restricted Based on COS] Explanation: TIE-to-CO Line Call Blocked by External Call Block Extension 1001 dials a number to make a TIE-to-CO line call. 1. The call is received at PBX-2 on CO line group 1, which has a COS of 3. 2. According to the TIE Line Routing and Modification Table of PBX-2 (not shown here), the CO line call should be made using CO line group 3, however, this CO line group is set to block COS 3 calls. TIE-to-CO Line Call Restricted by TRS Extension 1001 dials a number to make a TIE-to-CO line call. 1. The call is received at PBX-2 on CO line group 1, which has a COS of 3. 2. TRS programming for PBX-2 (not shown here) prohibits the call from being made based on the COS of CO line group 1. [Example of Bypassing TIE-to-CO Line Call Restrictions] Explanation: 1. Extension 1001 dials a DISA floating extension number of PBX-2. 2. The DISA feature answers the call. From this point, if the COS assigned to the caller's extension or verified code allows, the caller can use Walking COS or Verified Code Entry to bypass the restrictions and make a CO line call. d) TIE Line Call Routed to CO Line via FWD/Intercept Routing/Call Transfer A TIE line call can be redirected to an outside party via FWD, Intercept Routing, or Call Transfer. [Example] Explanation: PBX-1 makes a call. Extension 1001 of PBX-1 dials "2001". 1. PBX-1 checks its Extension Numbering Plan. "2001" is not one of its extensions. 2. PBX-1 checks its Other PBX Extension list, and finds an extension "2001". 3. PBX-1 checks its TIE Line Routing and Modification Table (not shown here). Finds leading number "2". No modification is programmed. 4. Sends the call down the TIE line. PBX-2 receives the call. 1. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. The number is still "2001". 2. PBX-2 checks its Extension Numbering Plan. "2001" is one of its extensions. 3. PBX-2 sends the call to extension 2001. 4. Calls directed to extension 2001 are redirected to the outside party (1-212-555-1234) because of one of the following: a) This number is programmed (not shown here) as the FWD or Intercept Routing destination for calls to extension 2001. The destination is programmed as "9-12125551234". b) The extension 2001 user transferred the call to the outside party by dialing "9-12125551234". 3.3. CO-to-TIE-to-CO Line Calls An incoming CO line call can be routed to the DISA feature of a PBX, then the caller can make a CO line call which is routed via ARS through another PBX. [Example] Explanation: The outside caller dials a telephone number which is routed to the DISA feature of PBX-1, then dials the Idle Line Access number of PBX-1 "9", followed by the desired outside party's telephone number "1-212-555-1234" 1. The Idle Line Access number "9" was dialed, therefore PBX-1 modifies the dialed number via its ARS programming (not shown here). It removes the first digit "9", adds the Idle Line Access number of PBX-2 "9", and sends the number down the TIE line to PBX-2. The number is now "9-12125551234". 2. PBX-2 checks its Incoming Number Modification Table (not shown here). No modification is programmed. 3. PBX-2 recognizes its Idle Line Access number, "9", and sends the remaining number, "12125551234", to the telephone company using an idle CO line.

Conditions

•	PBX Code If a PBX is assigned a PBX code, it will not handle calls received via TIE line with the Extension Number Method (Access without PBX Code). Only assign a PBX code when using PBX Code Method (Access with PBX Code). ( 1.26.1.2 PBX Code Method (Access with PBX Code))
•	When a TIE line call arrives at an extension, it is treated as a CO line call, not as an intercom call. If the called extension is busy and has disabled Call Waiting, the caller will hear a busy tone or be redirected to the Intercept Routing–Busy destination, if one is programmed. If the called extension has set Do Not Disturb (DND), the call will be redirected to the Intercept Routing–DND destination, if one is programmed. ( 1.1.1.5 Intercept Routing)
•	The amount of time the PBX waits for a digit to be dialed before sending a reorder tone can be specified through system programming (TIE Receiving Dial Inter-digit time).
•	Throughout the examples in this section, the CO Line Group Access number "8" and a CO line group number ("02", for example) can be dialed instead of the TIE Line Access number "7" if the caller wishes to select a specific line group with which to make a call. Note, however, that if the TIE Line Access number is not dialed, the PBX will not check the TIE Line Routing and Modification Table for instructions on how to modify the dialed number before sending it down the TIE line using the specified CO line group.

Feature Guide References

User Manual References

1.26.2 QSIG Network

1.26.2.1 QSIG Network–OVERVIEW

Description

TIE line service can be used on a private network that is established using ISDN (PRI) lines programmed to implement the QSIG protocol (Q.931). QSIG offers TIE line service as well as advanced caller and called party identification features. When configuring Panasonic Hybrid IP-PBXs to establish a private network based on QSIG, the ports of each PBX must be programmed so that each ISDN line has a "master" connection and a "slave" connection.

[Example of Private Network Established via QSIG]

The following services are available when TIE line calls are made on a private network established via QSIG. They can be enabled or disabled for each ISDN (PRI) port.

Service Description Details in Calling Line Identification Presentation (CLIP) When a call is made, the caller's extension number is sent to the other PBX. • 1.26.2.2 Calling/Connected Line Identification Presentation (CLIP/COLP) and Calling/Connected Name Identification Presentation (CNIP/CONP)–by QSIG Calling Line Identification Restriction (CLIR) When a call is made, the caller's extension number is not sent to the called party. Calling Name Identification Presentation (CNIP) When a call is made, the caller's extension name is sent to the other PBX. Calling Name Identification Restriction (CNIR) When a call is made, the caller's extension name is not sent to the called party. Connected line Identification Presentation (COLP) When a call is answered, the extension number of the answering party is sent back to the caller's PBX. Connected Line Identification Restriction (COLR) When a call is answered, the extension number of the answering party is not sent back to the caller's extension. Connected Name Identification Presentation (CONP) When a call is answered, the answering party's extension name is sent back to the caller's PBX. Connected Name Identification Restriction (CONR) When a call is answered, the answering party's extension name is not sent back to the caller's extension.

Feature Guide References

1.26.2.2 Calling/Connected Line Identification Presentation (CLIP/COLP) and Calling/Connected Name Identification Presentation (CNIP/CONP)–by QSIG

Description

When TIE line calls are made on a private network established via QSIG, QSIG offers several features which can be used to present or hide the identification of both the caller and the called party.

Calling Line/Name Identification Presentation (CLIP/CNIP) Similar to Caller ID, when an extension user makes a TIE line call, the PBX can send the caller's extension number and/or extension name to the called party of the other PBX. This information can be shown on the display of the called party before answering the call.

[Example of CLIP/CNIP]

Connected Line/Name Identification Presentation (COLP/CONP) When an extension user answers a TIE line call, the PBX can send the answering party's extension number and/or extension name to the caller. This information can be shown on the display of the caller, so the caller will know who answered his or her call. This feature is useful in situations where a call is answered by someone other than the called party, such as when the call is redirected to another extension by Call Forwarding (FWD) or Intercept Routing, for example, or when a call is directed to an incoming call distribution (ICD) group.

[Example of COLP/CONP when the Call is Forwarded or Intercepted]

[Example of COLP/CONP when the Call is Directed to an ICD Group]

CLIP/COLP Number The number sent to the other PBX by CLIP/COLP is the number assigned to the extension through system programming ( Extension Number [003]).

CNIP/CONP Name The name sent to the other PBX by CNIP/CONP is the name assigned to the extension through system programming ( Extension Name [004]).

Calling Line/Name Identification Restriction (CLIR/CNIR) An extension can select to restrict the sending of its extension number and name when making a call by entering the CLIR feature number or by pressing the CLIR button. When CLIR is activated, CNIR is activated automatically.

Connected Line/Name Identification Restriction (COLR/CONR) An extension can select to restrict the sending of its extension number and name when answering a call by pressing the COLR button. When COLR is activated, CONR is activated automatically.

Conditions

Feature Guide References

User Manual References

1.26.3 Voice over Internet Protocol (VoIP) Network

Description

The Panasonic Hybrid-IP PBX can be used on a private network which implements Voice over Internet Protocol (VoIP). On this type of network, information is sent over the private network in IP packets, which allows voice as well as data to be sent to other devices in the private network. Each PBX in the private network is connected via an IP-GW card to a local area network (LAN). A LAN can consist of PBXs, computers, servers, routers, etc. Each LAN is connected to the private network by a router, which is used to direct voice and data to the routers of other PBXs. These routers can be connected by privately leased lines. TIE line service and QSIG services can be used on a private network which implements Voice over Internet Protocol (VoIP). ( 1.26.1 TIE Line Service, 1.26.2 QSIG Network)

[Example]

Conditions