Tài liệu PBX Networking Standard Telephony pdf

Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-1 © 2000, Cisco Systems, Inc. www.cisco.com Networking - 791-1 PBX NetworkingPBX Networking PBX Networking Standard Telephony Standard Telephony Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-2 Networking - 791-2 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com Module Objectives Module Objectives Upon completion of this chapter, you will be able to: • Describe typical PBX network applications • Identify the types of signaling used in PBX networks • Define the proprietary PBX protocolsfrom Lucent & Nortel • Identify design issuesrelated with integrating PBX traffic over data networks for both Lucent and Nortel PBXs Upon completion of this chapter, you will be able to: • Describe typical PBX network applications • Identify the types of signaling used in PBX networks • Define the proprietary PBX protocols from Lucent & Nortel • Identify design issues related with integrating PBX-traffic over data networks for both Lucent and Nortel PBXs Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-3 Networking - 791-3 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com Module Content Module Content I. PBX Review II. PBX Signaling A. Analog B. Digital III. General Design Implications More specifically, this module focuses on a review of PBX. Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-4 Networking - 791-4 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com PBX Benefits PBX Benefits • Allows many phones in an office to share fewer number of “outside lines,” controlling cost growth • Supports features – Short-number extensions – Conferencing – Forwarding – Security restrictions – Lowest cost and other policy-based routing – Manipulation of outgoing and incoming digits – Park, etc. • Provides for sophisticated selection of route, i.e., saves on toll costs • Provides detailed use records There are many benefits of PBX. •It allows many phones in an office to share a fewer number of outside lines, which helps to control cost growth. •It supports many different features, including: • Short-numbering extensions • Conferencing • Forwarding • Security restrictions • Lowest cost and other policy-based routing • Manipulation of outgoing and incoming digits • Park, etc. •It provides for sophisticated selection of route, i.e., it saves on toll costs •It provides detailed use records Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-5 A private branch exchange (PBX) cabinet is a metal housing designed to hold the electronic components that make the PBX work. Each cabinet contains one or more shelves, or carriers with slots. Each shelf in the PBX accepts a certain number of circuit boards. There are different types of circuit boards within a PBX, including the following: • Both-way trunk circuit boards—Supports both-way trunks or combination trunks that receive incoming calls or place outgoing calls. • DID trunk circuit boards—Support a special type of trunk used for incoming direct inward dialing (DID) calls only. • Universal trunk circuit boards—Mix both-way trunks, DID trunks, loop-start tie trunks on the same board. Also support Recorded ANnouncement (RAN), overhead paging, and music-on-hold. • ISDN circuit boards—Support lines connecting the PBX and another device over an ISDN PRI or BRI. PRI and U-Interface BRI are point- to-point. S/T-Interface BRI is point-to-multipoint. Networking - 791-5 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com Circuit Boards Circuit Boards Need slide on Circuit Boards Need slide on Circuit Boards Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-6 Extra Text • Tie trunk circuit boards—Support point-to-point lines connecting two PBXs so that the users of both systems may communicate with each other without per-minute toll charges. Most analog Ear and Mouth (E&M) tie- trunk circuit boards handle two or four tie trunks. • T1/E1 circuit boards—Multiplexers that support a high-capacity T1 or E1 circuit, enabling up to 24 (T1) or 30 (E1) voice conversations at one time. Recall that T1 is the term used for a DS-1 signal carried over two copper pairs. T1 is a type of line that is not a signaling type. • Digital telephone circuit boards—Support digital telephones. The analog voice signal converts to a digital form at the telephone and goes back to the PBX as pulse code modulated (PCM) encoded bytes. • Analog telephone circuit boards—Support analog telephones, as well as fax machines, computer modems, and any other device which utilizes a plain old telephone service (POTS)-type loop start analog interface. • DTMF receiver circuit boards—Contain dual tone multifrequency (DTMF) receivers. • MF receiver circuit boards -Contain multifrequency (MF) receivers. • Tone sender boards -Generate all the tones for a system, including dial tone, busy tone, DTMF, MF, and CLASS. • Common control circuit boards—Central processing unit of the PBX. When two PBXs communicate over non-ISDN tie trunks, they can use E&M signaling, among others. Networking - 791-6 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com Circuit Boards Circuit Boards Need slide on Circuit Boards Need slide on Circuit Boards Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-7 Networking - 791-7 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com Wide-Area PBX Networking Wide-Area PBX Networking • PBX trunking/transport – Example of services for long-distance calls 10s 100s 10s 100s Switch CO CO NYLA CO Trunks Tie Trunks 213–666–5678 212–345–2424 CO Trunks Tie Trunks PSTN FX 416 526–1234 Switch PSTN IXC This graphic depicts typical legacy PBX-to-PBX connectivity connecting two PBXs in different local access and transport areas (LATAs). The actual connections are from the PBX to the local exchange carrier (LEC), for example, the central office (CO) switch then to a LEC tandem switch. From there the connection is made to an inter exchange carrier’s (IXC) point-of-presence (POP), then into the IXC network cloud. The connections at the other end follow the reverse path. Tie-trunks are generally cross-connected (hard-wired) instead of switched at the LEC (CO) and IXC level. If they are configured to go into a LEC/IXC switch, they are configured as dedicated nailed-up circuits. Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-8 Networking - 791-8 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com 10s 100s 10s 100s 10s 100s 10s 100s CO CO NYLA CO Trunks Tie Trunks 213–666–5678 212–345–2424 CO Trunks Tie Trunks QoS WAN Internet/Intranet FX (212) 526–1234 Switch Switch PSTN PBX Connectivity over Data Network PBX Connectivity over Data Network Route Replacement The graphic shows a generic but typical start of using a data network for PBX-to-PBX connectivity. The enterprise still has its legacy connections. Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-9 Networking - 791-9 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com The PBX “Stack” The PBX “Stack” PBX Line Service Types PBX Signaling PBX Services PBX Supported Applications Hold Forward Park Conference Building Page Networking Local Extensions CCS,CAS, QSIG, Digital (PBX-to-PBX) E&M, Proprietary Digital (PBX-phone) Tie trunks CO trunks DID trunks FX trunks RAN trunks Subscriber lines Analog/Digital IVR ACD Voice Mail Msg on Hold Call Center Loop-type analog, T1,E1,n-wire, PRI, BRI Physical Line Type The PBX stack is a representation of the various layers of functionality supported by a PBX. The lists of items for each layer are illustrative and not complete. You may also think about other components that provide line and trunk supervision and signaling methods:. For analog and channel associated signaling (CAS): • Seizure and disconnect supervision: loop-start, ground start, E&M, loop dial repeating • (Dial) starting arrangements: Wink-start, immediate dial, delay dial • Addressing methods: DTMF, MF, dial pulse • Answer supervision: Battery reversal, E&M control lead signaling For ISDN: • Access line type: BRI (DSL), PRI (T1 or E1) • Line protocol: For BRI: U (2B1Q) or S/T (pseudo-ternary); for PRI: DS1 or E1 • D channel protocol: NI-2, QSIG, DMS custom, AT&T custom, Nortel MCDN custom Designing Voice over Data—PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc. 2-10 Networking - 791-10 Designing Voice over Data —PBX Integration with Data Networks © 2000, Cisco Systems, Inc. www.cisco.com PBX Circuit Types PBX Circuit Types SwitchSwitch SwitchSwitch Central Office Central Office (CO) “FX” Tie Lines Analog 2/4 wire type 1-5 Digital 2/4 wire Analog 2 wire 2 wire E&M, 2/4 wire 5 types “FX” Analog 2/4 wire type 1-5 1 3 4 5 6 T1 tie line FXO interface FXO interface 2 Analog Analog trunk circuits connect automated systems (such as a PBX) and the network (such as a central office). The most common form of analog tie trunk is the E&M interface. Like a serial port, E&M has a DTE/DCE type of reference. In the telecom world, the “trunking” side is similar to the DCE, and is usually associated with CO functionality. The Cisco 3600 acts as this side of the interface. The other side is referred to as the “signaling” side, like a DTE, and is usually a device such as a PBX. There are five distinct physical configurations for the E&M interface (types 1-5), and two distinct flavors of audio interface (2-wire or 4-wire). Note that even though it may be called a 4-wire E&M circuit, it is likely to have 6 to 8 physical wires! The difference between a 2-wire and 4-wire circuit is whether the audio path is full duplex on one pair or two pairs of wires. The foreign exchange office (FXO) interface (typically an interface card) supports the CO side loop-start line. The foreign exchange station (FXS) supports the station-side of the loop-start line. Foreign exchange (FX) is the term used historically to describe the PBX or telephone instrument connection to a remote CO. Typically the “FX line” was used to get local, toll-free dialing in another LATA. Digital Digital T1/E1trunk circuits are 4 wire. In Europe, and soon in North America, ISDN BRI can be used as a trunk. The BRI U-interface is 2-wire. Subscriber lines may be 2- or 4-wire. They support several typical analog signaling protocols, both in-band and out-of-band, ISDN, and analog emulation. [...]... E&M—Used for PBX dial tie trunks or carrier systems – The best way to connect switches together using analog facilities Station Loop Signaling PBX- to -PBX Signaling, or PBX to CO Signaling CO Side Loop Start Line Station Side Loop Start Line PBX Designing Voice over Data PBX Integration with Data Networks E&M Trunk www.cisco.com Station Side Loop Start Line PBX or CO Switch © 2000, Cisco Systems, Inc Networking. .. proprietary inter -PBX digital signaling (CCS structure of ISDN PRIs): – Nortel uses MCDN – Siemens uses CORNET – Lucent uses DCS – Alcatel uses ABC – BT uses DPNSS • Benefit – PBX features can be supported network-wide – E.G., call redirect, follow-me, call forwarding, call waiting, caller id Designing Voice over Data PBX Integration with Data Networks Voice Mail PBX2 www.cisco.com PBX- toPBX-toPBX PBX Tie Line... Data PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc 2-35 Networking PBXs Full Mesh Configuration • Full mesh configuration – Requires n(n-1)/2 Links – Here: 4x3/2=6 Tie Trunks – Costly or impractical • Work-around is use of “tandemed PBXs” PBX2 BX -P -to k X n PB Tru Tie PB XTie to -P Tru BX nk PB XTie to - P Tru BX nk PBX- toPBX Tie Trunk X - PB to X - unk PB Tr Tie Inter -PBX. .. Switch CO PBX Private network Digital • • • • T1/E1 CAS/CCS PRI D channel Proprietary protocols (PBX -to -PBX) DASS#2 (time slot 16 of E1) Designing Voice over Data PBX Integration with Data Networks www.cisco.com © 2000, Cisco Systems, Inc Networking - 791-25 This graphic is an overview of PBX- to-CO and PBX- to -PBX legacy connectivity Typically, the connection is a T1 in North America, Japan, Taiwan, and... over Data PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc 2-13 Module Content I PBX Review II PBX Signaling A Analog B Digital III General Design Implications Designing Voice over Data PBX Integration with Data Networks www.cisco.com © 2000, Cisco Systems, Inc Networking - 791-14 The next few slides will focus on the analog side of PBX Signaling Designing Voice over Data PBX Integration... Signaling: QSIG PBX2 • An open, international standard for networking multivendor PBXs – Features transparency within a heterogeneous network – Supports interworking with PSTN – Most PBX vendors agreed to implement Q S – Uses the D channel—Compatible with public/private ISDN I – Supports ITU-T standard supplementary services G • A cost-effective method for wide -area PBX networking • QSIG is based on ITU-T Q.93x... internationally standardized implementation of ISDN that emphasizes feature functionality between different brands of PBXs We will be covering these in depth later in this chapter Nortel calls CAS the digital trunk interface (DTI) Designing Voice over Data PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc 2-24 Digital Trunk Signaling: PBX- to-CO & PBX- to -PBX Switch PSTN CO Switch CO PBX Private... an RJ-45 connector Designing Voice over Data PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc 2-25 Digital Signaling: PBX- to-CO, PBX- toRouter Private Network Replacement PSTN Switch Switch CO CO Frame Relay/ATM • T1/E1 CAS/CCS • PRI D channel • Proprietary protocols (PBX- to -PBX) • DASS#2 (time slot 16 of E1) Designing Voice over Data PBX Integration with Data Networks Digital... to discuss the digital side of PBX Signaling There are both legacy standards-based signaling approaches and internationally standardized approaches Designing Voice over Data PBX Integration with Data Networks Copyright © 1999, Cisco Systems, Inc 2-23 Digital Trunk Signaling • Trunk (circuit) signaling – PBX- to-CO signaling – PBX- to -PBX tie trunk signaling • Digital signaling protocols – Channel associated...Module Content I PBX Review II PBX Signaling A Analog B Digital III General Design Implications Designing Voice over Data PBX Integration with Data Networks www.cisco.com © 2000, Cisco Systems, Inc Networking - 791-11 The next section of this presentation is going to discuss PBX signaling Designing Voice over Data PBX Integration with Data Networks Copyright © 1999, . Inc. www.cisco.com Networking - 791-1 PBX NetworkingPBX Networking PBX Networking Standard Telephony Standard Telephony Designing Voice over Data PBX Integration with Data Networks. Networks © 2000, Cisco Systems, Inc. www.cisco.com Wide-Area PBX Networking Wide-Area PBX Networking • PBX trunking/transport – Example of services for long-distance