© 2006 Cisco Systems, Inc. All rights reserved.ONT v1.02-1 Describe Cisco VoIP Implementations Introducing VoIP Networks. - презентация

1 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Describe Cisco VoIP Implementations Introducing VoIP Networks

2 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Benefits of Packet Telephony Networks

3 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Benefits of Packet Telephony Networks More efficient use of bandwidth and equipment Lower transmission costs Consolidated network expenses Improved employee productivity through features provided by IP telephony: –IP phones are complete business communication devices Directory lookups and database applications (XML) Integration of telephony into any business application –Software-based and wireless phones offer mobility. Access to new communications devices (such as, PDAs and cable set-top boxes)

4 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Packet Telephony Components

5 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Packet Telephony Components

6 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Two Basic Methods for Voice over IP

7 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Analog Interfaces

8 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Analog Interfaces Analog Interface TypeDescription FXSUsed by the PSTN or PBX side of an FXS–FXO connection FXOUsed by the end device (phone) side of an FXS–FXO connection E&MTrunk, used between switches

9 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Digital Interfaces

10 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Digital Interfaces InterfaceVoice Channels (64 kbps Each)Signaling Framing Overhead Total Bandwidth BRI21 channel (16 kbps)48 kbps192 kbps T1 CAS24 (no clean 64 kbps because of robbed-bit signaling) in-band (robbed-bits in voice channels) 8 kbps1544 kbps T1 CCS231 channel (64 kbps)8 kbps1544 kbps E1 CAS3064 kbps 2048 kbps E1 CCS301 channel (64 kbps)64 kbps2048 kbps

11 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Stages of a Phone Call

12 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Stages of a Phone Call

13 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Distributed vs. Centralized Call Control

14 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Distributed Call Control

15 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Centralized Call Control

16 © 2006 Cisco Systems, Inc. All rights reserved.ONT v Summary Companies can benefit from a common infrastructure that serves voice and data. Advantages of such converged networks include lower costs, more efficient use of available bandwidth, and higher productivity. A packet telephony network consists of endpoints (such as IP phones, software phones, and video endpoints) and voice network devices (such as gateways, gatekeepers, conference bridges, call agents, and application servers). A voice gateway can use FXS, FXO, and E&M interfaces to connect to analog equipment, such as phones, PBXs, or the PSTN. A voice gateway can use BRI, T1, and E1 interfaces to connect to digital equipment, such as ISDN phones, PBXs, or the PSTN. A voice call consists of three stages: call setup, call maintenance, and call teardown. With distributed call control, each gateway has local intelligence to route calls, while with centralized call control, a call agent makes call routing decisions on behalf of all the gateways that are controlled by the call agent.

17 © 2006 Cisco Systems, Inc. All rights reserved.ONT v