BTE

Solution Overview Broadband Telephony Enabler

BTE

Solution Overview Broadband Telephony Enabler

Table of Contents

1 INTRODUCTION 5

1.1 Overview 5

1.2 Benefits 6

1.3 Building blocks 6

2 FEATURES AND FUNCTIONALITY 7

2.1 Telephony and fax services 7

2.2 Number analysis and routing functions 8

2.3 System scalability and reliability 9

2.4 System Management 10

2.5 Billing 11

2.6 System interoperability 11

3 SYSTEM ARCHITECTURE AND COMPONENTS 13

3.1 Network overview 13

3.2 BTE Gatekeeper 14

3.3 BTE Gateway 14

3.4 BTE Signaling Gateway 15

3.5 BTE Media Server 16

3.6 BTE Element Manager 17

4 PRODUCT SPECIFICATION 18

5 ABBREVIATIONS 22

Introduction

5

1 Introduction

1.1 Overview

IP-telephony has been discussed for some years, but not until now the concept has gained true acceptance. At the moment the main part of the IP-telephony installations are in the Enterprise segment. The residential use of IP-telephony has mainly been focused on free or almost free long-distance traffic over Internet. As broadband access is becoming more common, the residential IP-telephony is getting a new application area creating new revenue streams.

With IP-telephony broadband operators can offer end users telephony over always-on broadband connections. This enables new operators to offer 1st line telephony without investing in circuit switched equipment and incumbents to offer 2nd and 3rd line telephony over the broadband network.

Even if the standardization of broadband telephony is progressing rapidly, there are still a number of pitfalls when it comes to services, quality and security. For this reason 42Networks is promoting a fully tested end-to-end solution built on Quality, Security and Simplicity, bringing operators services that work not only today, but also in the future as the rollout of the different components is synchronized.

The BTE System is a part of an 42Networks end-to-end VoIP solution consisting of the BTE (Broadband Telephony Enabler) and the DRG (Digital Residential Gateway). BTE is an IP-telephony system with gatekeepers, gateways and a number of other components, supporting from a few hundred up to hundreds of thousands of IP-telephony end users. DRG is a customer premises equipment (CPE) for connecting end users to the telephony services through standard analog telephones and simultaneously enabling high quality connectivity for further broadband services.

Introduction

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1.2 Benefits

With BTE 42Networks can offer a carrier grade IP-telephony solution.

Broad range of services Most used class 5 services implemented (Call Forwarding,

CLIP/CLIR, Call Restriction, Call Barring, Call Waiting, 3-party Conference, etc)

IN services (VPN, Calling Card service, etc) Clearinghouse

Trusty carrier-grade system with scalability Flexible scalability from hundreds to hundreds of thousands of

end users High availability mode with back-up system providing 99,999%

availability

Flexible interoperability Signaling interoperability with No. 7 signaling network Interoperability with VoIP elements (Gateways, MGW, MGC,

CPE, PC Clients etc) Complies with current international standards (H323, SNMP,

RADIUS, etc)

1.3 Building blocks

The Broadband Telephony Enabler consists of the following building blocks:

• BTE Gatekeeper

• BTE Gateway

• BTE Signaling Gateway

• BTE Media server (IVR)

• BTE Element Manager 42Networks can also offer end user equipment for IP-telephony (e.g. Digital Residential Gateway) and different broadband solutions (e.g. Fiber Ethernet Access). These solutions are not a part of BTE, but are fully compatible and well integrated.

Features and functionality

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2 Features and functionality

2.1 Telephony and fax services

The intention of 42Networks VoIP solution is not primarily to replace today’s PSTN network with an identical IP copy. Even if BTE supports the most common class 5 services, the central concept is to provide additional value to operators, such as enabling integration of Internet access, voice and video in one network. In addition to standard class 5 services BTE supports services such as prepaid calling cards and VPN.

2.1.1 Basic services

Services such as Call forwarding, CLIP (Calling Line Identification Presentation), CLIR (Calling Line Identification Restriction) are all supported by BTE. Together with 42Networks Customer Premises Equipment, DRG, services like Call Waiting and 3-party conferences are also supported.

2.1.2 Barring and restricting calls

The call barring service allows the operator to block calls to and/or from a specific end user number. An announcement from the Media Server system will let the caller know that the line is blocked.

The call restriction service makes it possible to block certain end users from making certain types of calls. The types of calls possible to block are local, long distance and international.

2.1.3 User group

User Groups (UG) enable end users to form groups without changing any legacy environment, such as PBX or Key phone, already implemented in enterprise. Members of specific user group can communicate with each other with enterprise’s own numbering plan.

2.1.4 Voice announcements

Voice announcements for various services are supported by the BTE Media Server. For example voice announcements can be used to notify a calling end user that a called end user is absent.

Features and functionality

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2.1.5 Presentation of own number

The presentation of own number feature allows an end user to request which number the end user terminal he is calling from has, e.g. when starting up a conference call. The number is presented by a voice announcement.

2.1.6 Carrier pre-selection

With this feature the BTE operator can allow an end user to use a pre-selected carrier for all calls.

2.1.7 Pre-paid/Post-paid Calling Card

The Calling Card service allows users to access the BTE system through alternative access units, e.g. public payphones. The call is charged to the user’s regular telephone account.

The Pre-Paid service allows the operator to implement pre-paid accounts to minimize credit losses and improve cash flow. This also allow for easy integration with third party billing systems.

2.1.8 Voice Virtual Private Network (VPN)

The Voice VPN service is useful when implementing a private numbering plan in the network. The VPN service enables end users to make calls with private numbers.

2.1.9 Fax Support

BTE includes advanced support for Fax over IP. The fax handling function in the gateways monitors every operation between the fax terminals, and can interact with them to, e.g force the faxes to choose a less bandwidth demanding transmission speed, or to stimulate the fax terminals to avoid time out due to long network delays.

2.1.10 Emergency calls

BTE guarantees that emergency calls are set-up even though end-user is restricted to make a call.

2.2 Number analysis and routing functions

To allow operator and service provider to design efficient networks based on service types BTE offers a variety of routing functions fully comparable to those provided in circuit switched networks. BTE supports e.g. multiple area codes, longest matched prefix and incoming/outgoing trunk number translation based on routes. The routing can be based on least cost, traffic type, ratio or can be time dependent.

Features and functionality

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2.3 System scalability and reliability

BTE is economically scalable already from a few hundreds of users up to hundreds of thousands of users. BTE is designed for carrier class service and can therefore be configured in redundant mode. The high availability mode provides 99,999% uptime for the system.

2.3.1 Scalability

Using standard UNIX platforms in the Gatekeeper, Media Server and Signaling Gateway, the call handling capacity can be increased by simply adding CPU, memory and disc unit capacity. In Signaling Gateway also additional No.7 signaling boards are required.

The BTE Gateway is based on AudioCodes Mediant2000 product line. It is a scalable solution for 1, 2, 4, 8 and 16 E1’s and provides convenient upgrades with software keys. The BTE Gateway does not require any 3rd party hardware.

42Networks makes a recommendation for used configuration on installation or upgrade basis.

2.3.2 Redundancy structure

In the high availability mode the BTE system has an uptime of 99,999%.

The high availability gatekeeper system consists of two systems, the active and the standby system. The systems share a virtual IP address and continuously communicate with each other, checking the heart beat and the data synchronization. This way the standby system can automatically take over the responsibilities of the active system, without any time loss. Since the end terminals only have to be configured for one single IP address, the terminals will not notice a shift from the active to the standby system.

Other components in the system can also be configured in the high availability mode, either in active/standby mode (signaling gateway) or in load sharing mode (gateway and media server).

2.3.3 Mean Time Between Failure (MTBF)

System MTBF is affected by a number of factors, such as hardware and software failures and operational errors. BTE has a higher MTBF than the generally required 5 000 hrs.

2.3.4 Security

Security is one of the most elementary requirements in a VoIP network. Security is an issue that has to be considered in all network components and on all OSI model layers.

Features and functionality

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42Networks has secured the communication between the BTE and the end user equipment. Using e.g. 42Networks DRG as end user equipment this is solved by triangular authentication between the DRG, the Element Management and the gatekeeper as well as using H.235 based tokens on call-by-call basis.

2.3.5 QoS

BTE offers several means to utilize the Quality of Service of the underlying network. Since most of these mechanisms are dependent on a good network planning, 42Networks can also provide the services necessary to properly configure the network.

2.4 System Management

The BTE Element Management System provides operators and service providers with the possibility of fault management, configuration management, performance management, security management and operator management. With the Graphical User interface version features like performance management and statistics can be added.

2.4.1 User-friendly flexible interfaces

The BTE management system is provided with user-friendly interfaces, either a Graphical User Interface (GUI) or a Web Command Line Interface (CLI) Based. Web access allows the operator to check the status also from remote locations. For integration with e.g. existing Network Management Systems (NMS), the management system supports SNMP. Interfaces to Customer Care and Billing (CCB) can be provided based on customer requirements.

2.4.2 Real-time fault management

The BTE management system offers real-time fault data collection and reporting. System faults are detected through continuous automatic monitoring and through automatic tests. Failures are displayed either as audible or visible alarms according to a classification system with four stages.

2.4.3 Configuration management

The BTE management system makes it easy to manage the system configuration of system components. The system configuration and software version are displayed and can be downloaded via the Web CLI or GUI Interface.

Features and functionality

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2.4.4 Performance management/statistics

With the GUI based BTE management system performance management and statistics can be added. A number of real-time counters allow the operator to monitor the current situation in any part of the network at any time. Performance measurement parameters and threshold values can be registered, modified and deleted by the operator. The performance reports are presented as graphs or tables. Statistical data is offered based on a chosen time period (hour/day/week/month).

2.5 Billing

BTE is designed to have an open interface towards billing systems, supporting RADIUS/FTP. Call Detail Records (CDR) for the billing system can be generated both in the active and the standby system, ensuring a seamless billing process in case of a system shift.

A detailed CDR is created for each call and telephony or fax service. The record format can be changed according to customer requests. For enhanced security the CDR data is stored if transportation to the billing system is not completed. After recovery the CDR can be transported either manually or automatically.

Billing systems can be recommended on customer request.

2.6 System interoperability

Support for standard protocols is of high importance for the smooth integration of the BTE system with other network elements. BTE supports standard protocols for the interfaces shown in the picture below.

Features and functionality

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2.6.1 PSTN Networks

BTE enables interconnection between the IP Network and the No. 7 signaling network through supporting SS7 ISUP, with a number of national variations e.g. China. BTE also has support for ISDN PRI and R2-MFC for interoperability with the PSTN Network.

2.6.2 Other VoIP networks and end user equipment

For interoperability with other VoIP networks and end user equipment BTE supports the voice protocols H323. Both end user gateways and SoftPhones can be connected. BTE also supports MGCP, a feature not further described in this document. SIP, Session Initiated Protocol, will be supported in coming releases. BTE has been interoperability tested with equipment from several VoIP equipment vendors on the market.

2.6.3 Billing and Customer Care

BTE supports interoperability with several of the most common billing system through open Radius/FTP interfaces.

2.6.4 Management systems

The BTE management system can be integrated with the operators existing Network Management Systems through an SNMP based interface.

2.6.5 Authentication, Authorization and Accounting (AAA)

BTE has a built-in AAA Server in the gatekeeper for authentication and authorization of clients and for accounting. If the operator wish to integrate the BTE system with existing, external AAA systems for calling card applications, the BTE has a RADIUS interface.

AAA Customer Care & Billing

Network Management

PSTN

Other VoIP Networks

H.323

RADIUS/FTP

H.323

SS7 ISUPISDN-PRIR2

RADIUSSNMP

End user equipment

BTE

AAA Customer Care & Billing

Network Management

PSTN

Other VoIP Networks

H.323

RADIUS/FTP

H.323

SS7 ISUPISDN-PRIR2

RADIUSSNMP

End user equipment

BTE

System architecture and components

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System architecture and components

3.1 Network overview

The BTE system is based on a number of components according to the picture below:

BTE Media Server (optional)

BTE Element Management System

BTE Gatekeeper

BTE Signaling Gateway

10/100/1000 Base-T

Ethernet

IPNetwork

SS7

PSTN

CPE (DRG)

BTE Gateway

System architecture and components

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3.2 BTE Gatekeeper

The BTE Gatekeeper (GK) is a central component in the BTE system and serves three main purposes:

• Performs authentication, registration and call control functions of H323 based endpoints such as GW, PC client and CPE (e.g. 42Networks DRG).

• Provides carrier-grade network services (e.g international/long distance calls, packet tandem switching and inter-domain carrier services) and hosted global business services (e.g. voice VPN, conferencing and calling card services)

• Provides class 5 level services to enable voice services for broadband access subscribers.

The BTE GK uses SLEE (Service Logic Execution Environment) architecture, which allows operators to provide various enhanced services that can generate additional revenues and provide unique end-customer features.

The modular and scalable architecture of the BTE GK is designed for easy capacity expansion. The architecture supports cost efficient deployment from few subscribers to extensive global networks.

An exceptional reliability can be provided through redundant architecture that ensures seamless service operation. This is achieved as BTE Gatekeepers can be configured in high availability mode consisting of active and hot stand-by units. In an event of a node failure the BTE GK dynamically reconfigures the relevant Gatekeeper zone and performs a recovery process.

3.3 BTE Gateway

The BTE Gateway (GW) is based on AudioCodes Mediant2000 product line. It links the circuit switched network with packet switched IP networks to carry voice, data and fax traffic using the H.323 protocol. The Gateway application in the BTE System serves two main purposes:

• To map (encode and decode) the circuit switched network pulse Code Modulation (PCM) streams to and from voice packets on the IP network side.

System architecture and components

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• To map call control messages between any combination of supported circuit switched network (CSN) and packet switched network signaling protocols. The GW translates between the H.323 signaling on the packet switched side to ISDN PRI (Q.931) or R2-MFC. The ISUP signaling can be realised by using a stand-alone BTE Signaling Gateway.

The BTE GW supports various types of voice compressions mechanisms in order to match the available transmission capacity with the voice quality. Supported voice codecs are for example G.711, G.723.1, G.726, G.728 and G.729a. Real-time FAX over IP is supported according to the T.38 standard.

The BTE GW supports unique variety of powerful numbering and routing functions fully comparable to those provided in the circuit switched networks.

Other supported features are for example:

• Echo cancellation according to G.165 and G.168. The system covers echo and delay paths up to 32 ms (64 or 128 ms with reduced channel capacity).

• Modem detection and auto switch to PCM or ADPCM

• Voice Activity Detection (VAD) can be used to detect silence in the speech channel. During the silent periods, no voice packets are sent. To allow comfort noise, Silence Descriptor (SID) frames are transmitted.

• Dual Tone Multi Frequency (DTMF) detection for both in-band and out-band signaling is supported. DTMF is used for services where the end customer dials digits during the call (services like call forwarding).

• Dynamic jitter buffer for compensation of packet delay variations in the network. The buffer size is adapted automatically depending on the average delay.

3.4 BTE Signaling Gateway

The BTE Signaling Gateway (SG) is used when the H.323 network is connected to a No. 7 signaling network on the PSTN side. The Signaling Gateway performs the mapping between ISUP and Sigtran protocols.

42Networks BTE SG supports a number of standard and national ISUPs. It can be used as a signaling end point (SEP) when the traffic is terminated in BTE system. The SG can support multiple signaling point codes (SPC).

System architecture and components

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The BTE SG can be co-located with the voice Gateway or placed in a dedicated rack.

The BTE SG can work in a load-sharing mode. In event of a link failure the redundant unit automatically takes over the traffic from the faulty node. BTE SGs share a single signaling point code.

3.5 BTE Media Server

The BTE Media Server provides voice announcement functions enabling calling card services, absentee service, network announcements etc. It also works as a tool for other services built on two and three stage dialing models.

System architecture and components

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3.6 BTE Element Manager

The BTE Element Manager (EM) is a management system for operation, Administration and Maintenance (OAM) of the BTE product line. The BTE EM supports SNMP for integration to network management systems. The BTE EM main functions include configuration, fault and statistics management.

The BTE EM can be provided either in Web Command Line Interface (CLI) or Graphical User Interface (GUI) CLI version. In both versions web access allows the operator to check the status from remote locations.

Web CLI interface can be used in small to medium size installations. Web CLI supports for example following functionality:

• Operator Interface Management

• Configuration Management

• Connection Management

• Event Management

• Log Management

• Alarm Surveillance

• Performance Management

• Statistics Management

• Security Management

• Interfaces to other network management elements, billing systems etc.

In GUI CLI EM version the operator can connect both GUI and Web CLI based clients. Web Clients can be applicable for example for remote system status checks. GUI CLI EM version supports following features as an addition to features supported in the Web CLI version:

• Periodic Statistics Data Reports

• Traffic statistics and logs

• Traffic performance and logs

• Alarm statistics and logs

• Fault statistics and logs

The BTE Gateway is controlled with a stand alone Element Manager.

Product Specification

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4 Product Specification

BTE Gatekeeper

Control Intefaces

H.323 v 3.0 Radius

For prepaid/postpaid calling card services

Network Interfaces

LAN Interface 10/100 Base-T H323 Call control functions H.225.0 RAS signaling/H.225.0 call signaling/H.245 signaling Q.931 Gatekeeper routed call signaling, Q.931 + H.245 Gatekeeper routed call signaling H.323 Fast connect* H.245 Tunneling DTMF Relay Translating H.323 Alias (E.164/H.323 ID) Call Routing

Assigning route sequence group to connect a call by prefix Assigning special route sequence per prefix, Time dependent/ratio/least cost etc. Changing the called number of incoming call from specified route Changing the called number of a call terminated to specific route sequence Alarming when call completion ratio for specified route falls under the threshold value Supporting MAX call (incoming/outgoing) configuration per route Subscriber management functions Subscriber data management Subscriber authentication Status management of subscriber terminal (RMG/Terminal) Temporary pause of subscriber Malicious call trace CID on/off and changing per subscriber or terminating prefix

Registration/deletion/changing of subscriber data, auto back-up for subscriber data Periodic registration status management of terminal, status management of terminal by IRQ/IRR when a call is in service, supporting call status checking period CNIR (Calling/connected Name Identification Restrict)

Class 5 and Network services Calling Line Identification/Restriction, Call forwarding, Call restriction, Call barring, Carrier pre-selection, two stage dialing, Calling card, prepaid, VPN, UAN etc. Other features

CDR creation Supporting announcements with BTE Media server

Capacity (With SUN Ultra Sparcll 450MHz, 4 CPU) Concurrent voice/fax calls Calls per second Busy Hour Call Attempts Response Time CPU Load

50 to 7200 calls 70 calls/s Up to 252 000 max 250 ms 60%

Redundancy

Active/Hot standby redundancy

Product Specification

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BTE Gateway (Mediant2000)

Control Intefaces

H.323 MGCP SIP RTP/RTCP R2 MFC ISDN PRI

V 4.0 RFC 2705, MEGACO Numerous country variants ETSI Euro ISDN, ANSI NI2, DMS switch, Japan INS1500, QSIG basic call, Australian Telecom and others

Network Interfaces

LAN Interface PSTN Interface

Dual redundant 10/100 Base-T Up to 8 trunks using RJ-48c connectors 16 trunks using dual 50-pin Telco connectors

Call Routing Number analysis and routing functions Special routing functions Hunting groups

Multiple area codes, pre-assigned carrier, longest match prefix, overlap and enblock digit transportation, inbound/outband number transistion per route, insertion and deletion of digits, call restriction for specific prefix, direct route and up to 8 alternative routes, total route status management Routing per each traffic type of subscriber group and inband trunk routing, call distribution by ratio and/or time dependent routing, least cost routing Sequential/Circular/Random methods are selectable, Ascending/descending powers are selectable with Sequential/Circular methods

Media Support

Audio codecs Fax

G711, G723.1, G726, G728, G729a T.38 compliant group 3 fax relay

Quality of Service (QoS) Support VAD/Silence suppression Comfort noise Adaptive jitter buffer Echo cancellation

Voice Activity Detection ITU_T G.165 and G.168 Compliant with 32, 64* or 128* msec echo tail (*with reduced channel capacity)

Scalability 1, 2, 4, 8 and 16 E1/T1 per unit software upgradability between 1-2, 1-4, 2-4, 4-8, 8-16 as an option Redundancy

Load sharing

Product specification

20

BTE Signaling Gateway

Control Intefaces

H.323 v 3.0 No. 7 Signaling

Network Interfaces

LAN Interface PSTN Interface

10/100 Base-T E1/T1

No. 7 signaling MTP Processing ISUP message termination

MTP configuration establishment, MTP status management, MTP signaling message processing

Hardware configuration

Stand-alone or integrated with BTE Gateway Capacity with SUN Ultrasparcll 450MHz Response time ISUP call processing capacity Busy Hour Call Attempts HW capacity per Signaling Gateway

Average 100 ms, 95% within 250 ms 120 calls/s up to 432 000 2 E1/T1 terminations per board, 2 signaling links per E1/T1

Redundancy

Active/standby

BTE Media Server

Control Intefaces

H.323 v 3.0 RTP/RTCP

Network Interfaces

LAN Interface 10/100 Base-T Functionality Voice announcements Multiple language support Outband tone detection and collection Voice codecs

Fixed and editable announcements G711 A-law, G723.1, G729a

Hardware configuration

Stand-alone or integrated with BTE Gateway Capacity with SUN Ultrasparcll 900MHz 256 channels/processor max. 1000 concurrent calls/server

Redundancy

Load sharing

21

BTE Element Manager

Control Interfaces

Web CLI/GUI CLI Interface SNMP agent (version 2.0 or later) support Network Interfaces

LAN Interface Dual 10/100M BT Fault Management functions Fault status display Real-time alarm/fault detection Audible/Visual alarm/fault indications Fault profile (fault level, threshold etc.) Log Management Configuration Management functions System configuration display Software downloading & process status management System configuration & software version display Security Management functions Operator authentication Operator terminal authentication Operator Management functions Group configuration and management for equipment and users User account management Operator terminal management Command management functions Performance Management functions (GUI version only) System analysis through performance monitoring Query/registration/deletion of performance measurement parameters System resource (CPU/Disc) monitoring Query/configuration/modification of performance threshold value Performance report in table/graphical format Statistical Management functions (GUI version only) Periodical query of statistical data (hour/day/week/month) Traffic statistics Traffic performance statistics Alarm statistics Fault statistics Other management functions Advanced help Bullentin board for operators (GUI version only) Export function in excel format Various alternatives for graphical output of performance/statistics (GUI Version only) External database (GUI version only) Oracle Enterprise edition

Abbreviations

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5 Abbreviations

AAA Authentication, Authorization, Accounting ANSI American National Standards Institute BHCA Busy Hour Call Attempts BTE Broadband Telephony Node CCB Customer Care and Billing CDR Call Detail Record CLI Command Line Interface CLIP Calling Line Identification Presentation CLIR Calling Line Identification Restriction CORBA Common Object Request Broker Architecture CPE Customer Premises Equipment CPU Central Processing Unit CUG Closed User Group DRG Digital Residential Gateway DTMF Dual Tone Multi Frequency EMS Element Management System GK GateKeeper GUI Graphical User Interface GW GateWay HW HardWare IP Internet Protocol ISDN Integrated Services Digital Network ISUP ISDN User Part IVR Interactive Voice Response MGCP Media Gateway Control Protocol MS Media Server MTBF Mean Time Between Failure NMS Network Management System OAM Operation, Administration and Maintenance OS Operating System OSI Open Systems Interconnection OSP Operator Service Provider? PCM Pulse Code Modulation PRI Primary Rate Interface PSTN Public Switched Telephone Network QoS Quality of Service RADIUS Remote Authentication Dial-in User Service SEP SignallingSignaling End Point SG SignallingSignaling Gateway SID Silence Descriptor SIP Session Initiated Protocol SLEE Service Logic Execution Environment SMS Short Message Service SNMP Simple Network Management Protocol SP Soft Phone

Abbreviations

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SPC SignallingSignaling Point Codes SSL Secure Socket Layer VAD Voice Activity Detection VoIP Voice over Internet Protocol VPN Virtual Private Netork