Voice over Ip Fundamentals

by Davidson, Jonathan; Peters, James F.; Bhatia, Manoj; Kalidindi, Satish; Mukherjee, Sudipto

• ISBN13: 9781587052576
• ISBN10: 1587052571
• Edition: 2nd
• Format: Paperback
• Copyright: 2006-07-27
• Publisher: Cisco Press

Summary

A systematic approach to understanding the basics of voice over IP Understand the basics of enterprise and public telephony networking, IP networking, and how voice is transported over IP networks Learn the various caveats of converging voice and data networks Examine the basic VoIP signaling protocols (H.323, MGCP/H.248, SIP) and primary legacy voice signaling protocols (ISDN, C7/SS7) Explore how VoIP can run the same applications as the existing telephony system but in a more cost-efficient and scalable manner Delve into such VoIP topics as jitter, latency, packet loss, codecs, QoS tools, and security Voice over IP (VoIP) has become an important factor in network communications, promising lower operational costs, greater flexibility, and a variety of enhanced applications. To help you understand VoIP networks,Voice over IP Fundamentalsprovides a thorough introduction to the basics of VoIP. Voice over IP Fundamentalsexplains how a basic IP telephony infrastructure is built and works today, major concepts concerning voice and data networking, and transmission of voice over data networks. Yours"ll learn how voice is signaled through legacy telephone networks, how IP signaling protocols are used to interoperate with current telephony systems, and how to ensure good voice quality using quality of service (QoS). Even thoughVoice over IP Fundamentalsis written for anyone seeking to understand how to use IP to transport voice, its target audience comprises both voice and data networking professionals. In the past, professionals working in voice and data networking did not have to understand each otherrs"s roles. However, in this world of time-division multiplexing (TDM) and IP convergence, it is important to understand how these technologies work together.Voice over IP Fundamentalsexplains all the details so that voice experts can understand data networking and data experts can understand voice networking. The second edition of this best-selling book includes new chapters on the importance of billing and mediation in a VoIP network, security, and the common types of threats inherent when packet voice environments, public switched telephone networks (PSTN), and VoIP interoperate. It also explains enterprise and service-provider applications and services.

Author Biography

Jonathan Davidson, CCIE No. 2560, is the Director of SP Solution Engineering in Integrated Network Systems Engineering. He has co-authored Voice over IP Fundamentals and edited Deploying Cisco Voice over IP. He has been with Cisco for 10 years in post-sales support, marketing, and engineering divisions.

James Peters is the Director of Product Marketing in the Carrier Core and Multiservice Business Unit at Cisco Systems. He co-authored the first edition of Voice over IP Fundamentals and is currently authoring a book on multiservice networking. James has more than 20 years experience in building, designing Internet-based voice and data networks, and product development.

Manoj Bhatia is a Business Development Manager for Partner Programs at IP Communications Business Unit (IPCBU) for Cisco Systems, Inc. He was among the first to start the software development for SIP technology on Cisco VoIP gateways and IOS-based routers. His past projects include technical marketing for VoIP products such as media gateways, call agents, and SIP-based residential voice solutions. Prior to Cisco, Manoj worked in Nortel Networks and Summa Four (now Cisco) and has 14+ years of experience in telephony protocols such as SS7, call control, and VoIP technologies.

Satish Kalidindi is a Software Engineer with Cisco Systems. He has more than six years experience working on development and deployment of VoIP technologies. He has been involved with various products, including IOS gateways and Cisco CallManager. More recently he has been involved with security features on CCM. He is a graduate of Purdue University with an M.S in Engineering.

Sudipto Mukherjee is a Software Development Engineer with Cisco Systems. He has product development and deployment experience for a variety of telecommunication devices for wireline, wireless, and VoIP networks. More recently at Cisco he has been working on SIP gateway development. Sudipto has a Bachelors of Engineering degree in Electronics Communication engineering from GS Institute of Technology, Indore and a Masters degree in Electronics Design and technology from Indian Institute of Science, Bangalore.

 

Table of Contents

Introduction	xx
Part I PSTN	3	(124)
Overview of the PSTN and Comparisons to Voice over IP	5	(30)
The Beginning of the PSTN	5	(2)
Understanding PSTN Basics	7	(9)
Analog and Digital Signaling	7	(2)
Digital Voice Signals	9	(1)
Local Loops, Trunks, and Interswitch Communication	10	(1)
PSTN Signaling	11	(1)
User-to-Network Signaling	11	(2)
Network-to-Network Signaling	13	(3)
PSTN Services and Applications	16	(4)
PSTN Numbering Plans	18	(1)
NANP	19	(1)
ITU-T International Numbering Plan	19	(1)
Drivers Behind the Convergence Between Voice and Data Networking	20	(1)
Drawbacks to the PSTN	20	(1)
Packet Telephony Network Drivers	21	(9)
Standards-Based Packet Infrastructure Layer	22	(2)
Open Call-Control Layer	24	(1)
VoIP Call-Control Protocols	24	(1)
H.323	25	(2)
MGCP (Evolution from SGCP and IPDC)	27	(2)
SIP	29	(1)
H.248/MEGACO	29	(1)
Open Service Application Layer	30	(1)
New PSTN Network Infrastructure Model	30	(2)
Summary	32	(3)
Enterprise Telephony Today	35	(12)
Similarities Between PSTN and ET	35	(1)
Differences Between PSTN and ET	36	(1)
Signaling Treatment	36	(1)
Advanced Features	37	(1)
Common ET and PSTN Interworking	37	(8)
ET Networks Provided by PSTN	38	(1)
Simple Business Line	38	(1)
Centrex Line	39	(1)
VPN	39	(2)
Private ET Networks	41	(1)
PBX Networks	41	(2)
Tie-Lines for PBX Interconnection	43	(2)
Summary	45	(2)
Basic Telephony Signaling	47	(32)
Signaling Overview	47	(3)
Analog and Digital Signaling	47	(1)
Direct Current Signaling	48	(1)
In-Band and Out-of-Band Signaling	49	(1)
Loop-Start and Ground-Start Signaling	50	(1)
CAS and CCS	50	(1)
E&M Signaling	50	(4)
Type I	51	(1)
Type II	52	(1)
Type III	52	(1)
Type IV	53	(1)
Type V	54	(1)
CAS	54	(10)
Bell System MF Signaling	55	(1)
Supervision Signaling	55	(2)
Address Signaling	57	(1)
CCITT No. 5 Signaling	58	(1)
Supervision Signaling	59	(1)
Address Signaling	60	(1)
R1	60	(1)
R2	60	(1)
Supervision Signaling on Analog Trunks	61	(1)
Supervision Signaling on Digital Trunks	62	(1)
Inter-Register Signaling	63	(1)
ISDN	64	(9)
ISDN Services	65	(1)
ISDN Access Interfaces	66	(1)
BRI	66	(2)
PRI	68	(1)
ISDN L2 and L3 Protocols	68	(1)
Q.931 Call Control Messages	69	(2)
Basic ISDN Call	71	(1)
Call Setup	72	(1)
Call Disconnect	73	(1)
QSIG	73	(4)
QSIG Services	74	(1)
QSIG Architecture and Reference Points	74	(1)
QSIG Protocol Stack	75	(1)
QSIG Basic Call Setup and Teardown Example	76	(1)
DPNSS	77	(1)
Summary	77	(2)
Signaling System 7	79	(38)
SS7 Network Architecture	80	(9)
Signaling Elements	80	(1)
SSP	81	(1)
STP	82	(1)
Global Title Translation	82	(1)
STP Hierarchy	83	(1)
SCP	84	(1)
Signaling Links	85	(1)
Signaling Modes	85	(1)
Signaling Links and Linksets	86	(2)
Signaling Routes	88	(1)
Signaling Link Performance	89	(1)
SS7 Protocol Overview	89	(23)
Physical Layer---MTP L1	90	(1)
Data Layer---MTP L2	91	(1)
FISU	91	(2)
LSSU	93	(1)
MSU	94	(2)
Network Layer---MTP3	96	(1)
Message Format	96	(1)
SMH	97	(1)
Routing Overview	98	(2)
SNM Message Structure	100	(1)
Congestion Control	100	(1)
Rerouting	101	(1)
Changeover and Changeback	101	(1)
SCCP	102	(1)
Connection-Oriented Services	102	(1)
Connectionless Services and Messages	102	(2)
SCCP Connectionless Example	104	(1)
SCCP Management Functions	104	(1)
TUP	104	(1)
ISUP	105	(1)
ISUP Services	105	(1)
End-to-End Signaling	106	(1)
Call Setup and Teardown	106	(1)
ISUP Message Format	107	(1)
ISUP Call Control Messages	108	(1)
TCAP	109	(1)
TCAP Interfaces	110	(1)
Transaction Portion of TCAP	111	(1)
Component Portion of TCAP	111	(1)
SS7 Examples	112	(3)
Basic Call Setup and Teardown Example	112	(1)
800 Database Query Example	113	(2)
List of SS7 Specifications	115	(1)
Summary	115	(2)
PSTN Services	117	(10)
Plain Old Telephone Service	117	(2)
Custom Calling Features	118	(1)
Class Features	118	(1)
Voice Mail	119	(1)
Business Services	119	(3)
Virtual Private Voice Networks	120	(1)
Centrex Services	121	(1)
Call Center Services	121	(1)
Service Provider Services	122	(2)
Database Services	122	(1)
Operator Services	123	(1)
Summary	124	(3)
Part II Voice over IP Technology	127	(112)
IP Tutorial	129	(16)
OSI Reference Model	129	(4)
The Application Layer	130	(1)
The Presentation Layer	130	(1)
The Session Layer	131	(1)
The Transport Layer	131	(1)
The Network Layer	131	(1)
The Data Link Layer	132	(1)
The Physical Layer	132	(1)
Internet Protocol	133	(1)
Data Link Layer Addresses	134	(1)
IP Addressing	135	(2)
Routing Protocols	137	(2)
Distance-Vector Routing	138	(1)
Link-State Routing	138	(1)
BGP	138	(1)
IS-IS	138	(1)
OSPF	139	(1)
IGRP	139	(1)
EIGRP	139	(1)
RIP	140	(1)
IP Transport Mechanisms	140	(3)
TCP	141	(1)
UDP	142	(1)
Summary	143	(1)
References	143	(2)
VoIP: An In-Depth Analysis	145	(24)
Delay/Latency	146	(2)
Propagation Delay	146	(1)
Handling Delay	146	(1)
Queuing Delay	147	(1)
Jitter	148	(1)
Pulse Code Modulation	149	(2)
What Is PCM?	149	(1)
A Sampling Example for Satellite Networks	150	(1)
Voice Compression	151	(3)
Voice Coding Standards	152	(1)
Mean Opinion Score	152	(2)
Perceptual Speech Quality Measurement	154	(1)
Echo	154	(1)
Packet Loss	155	(2)
Voice Activity Detection	157	(1)
Digital-to-Analog Conversion	158	(1)
Tandem Encoding	158	(2)
Transport Protocols	160	(2)
RTP	161	(1)
Reliable User Data Protocol	162	(1)
Dial-Plan Design	162	(2)
End Office Switch Call-Flow Versus IP Phone Call	164	(3)
Summary	167	(1)
References	167	(2)
Quality of Service	169	(38)
QoS Network Toolkit	170	(2)
Edge Functions	172	(15)
Bandwidth Limitations	172	(1)
cRTP	173	(2)
Queuing	175	(1)
Weighted Fair Queuing	176	(1)
Custom Queuing	177	(1)
Priority Queuing	178	(1)
CB-WFQ (CB=Class Based)	179	(1)
PQ within CB-WFQ (Low Latency Queuing)	180	(1)
Queuing Summary	180	(1)
Packet Classification	180	(1)
IP Precedence	181	(2)
Policy Routing	183	(1)
RSVP	184	(3)
Traffic Policing	187	(10)
CAR	187	(2)
Traffic Shaping	189	(1)
Differences Between GTS and FRTS	190	(1)
Traffic Shaping and Queuing	190	(3)
Fragmentation	193	(1)
Blocking	194	(1)
MCML PPP	194	(1)
FRF.12	195	(1)
IP MTU and MTU	195	(2)
Edge QoS Wrap-Up	197	(1)
Backbone Networks	197	(3)
High-Speed Transport	197	(1)
Modified Deficit Round Robin	198	(1)
Congestion Avoidance	198	(1)
WRED	198	(1)
TCP	199	(1)
Backbone QoS Wrap-Up	200	(1)
Rules of Thumb for QoS	200	(1)
Cisco Labs' QoS Testing	201	(2)
Summary	203	(4)
Billing and Mediation Services	207	(14)
Billing Basics	207	(6)
Authentication, Authorization, and Accounting (AAA)	208	(1)
Radius	209	(1)
Vendor-Specific Attributes (VSA)	210	(1)
Billing Formats	210	(1)
Typical Telco Approach	210	(1)
Open Settlements Protocol (OSP)-Based Approach	211	(1)
Radius-Based Approach	212	(1)
IPDR-Based Approach	212	(1)
Case Study: Cisco SIP Proxy Server and Billing	213	(5)
Radius Server Accounting	215	(1)
Radius Interface for Cisco SPS	215	(2)
Prepaid and Postpaid Applications	217	(1)
Challenges for VoIP Networks	218	(1)
Mediation Services	218	(1)
Summary	219	(2)
Voice Security	221	(18)
Security Requirements	221	(1)
Security Technologies	221	(6)
Shared-Key Approaches	222	(1)
Public-Key Cryptography	222	(1)
Asymmetric Keys	222	(1)
Digital Signature	223	(1)
Certificates and Certificate Authority	224	(1)
Public-Key-Based Protocols	224	(3)
Protecting Voice Devices	227	(1)
Disabling Unused Ports/Services	227	(1)
HIPS	228	(1)
Protecting IP Network Infrastructure	228	(7)
Segmentation	228	(1)
Traffic Policing	229	(1)
802.1x Device Authentication	229	(1)
Layer 2 Tools	230	(1)
DHCP Snooping	230	(1)
IP Source Guard	231	(1)
Dynamic ARP Inspection	231	(1)
CAM Overflow and Port Security	232	(1)
BPDU Guard and Root Guard	232	(1)
Circumventing VLANs	233	(1)
NIPS	233	(1)
Layer 3 Tools	233	(1)
Authentication of Routing Updates	234	(1)
TCP Intercept	234	(1)
Security Planning and Policies	235	(1)
Transitive Trust	235	(1)
VoIP Protocol-Specific Issues	235	(1)
Complexity Tradeoffs	235	(1)
NAT/Firewall Traversal	236	(1)
Password and Access Control	236	(1)
Summary	236	(3)
Part III IP Signaling Protocols	239	(82)
H.323	241	(26)
H.323 Elements	245	(4)
Terminal	245	(2)
Gateway	247	(1)
Gatekeeper	247	(1)
The MCU and Elements	248	(1)
H.323 Proxy Server	249	(1)
H.323 Protocol Suite	249	(11)
RAS Signaling	250	(1)
Gatekeeper Discovery	250	(1)
Registration	251	(1)
Endpoint Location	252	(1)
Admissions	253	(1)
Status Information	253	(1)
Bandwidth Control	254	(1)
Call Control Signaling (H.225)	254	(3)
Media Control and Transport (H.245 and RTP/RTCP)	257	(1)
Fast Connect Procedures	258	(1)
Tunneling H.245	258	(1)
Call Termination	259	(1)
Media Transport (RTP/RTCP)	259	(1)
H.323 Call-Flows	260	(4)
Summary	264	(3)
SIP	267	(34)
SIP Overview	268	(3)
Functionality That SIP Provides	268	(1)
SIP Network Elements	268	(1)
Interaction with Other IETF Protocols	269	(1)
Message Flow in SIP Network	270	(1)
SIP Message Building Blocks	271	(9)
SIP Addressing	271	(1)
SIP Messages	272	(1)
SIP Requests	272	(1)
SIP Responses	273	(2)
SIP Message Structure	275	(2)
SIP Headers	277	(1)
SIP Transactions and Dialog	278	(2)
Transport Layer Protocols for SIP Signaling	280	(1)
Basic Operation of SIP	280	(4)
Proxy Server Example	280	(1)
Redirect Server Example	281	(2)
B2BUA Server Example	283	(1)
SIP Procedures for Registration and Routing	284	(7)
User Agent Discovering SIP Servers in a Network	285	(1)
SIP Registration and User Mobility	285	(2)
SIP Message Routing	287	(1)
Routing of Subsequent Requests Within a SIP Dialog	288	(3)
Signaling Forking at the Proxy	291	(1)
Enhanced Proxy Routing	291	(1)
SIP Extensions	291	(8)
SIP Extension Negotiation Mechanism: Require, Supported, Allow Headers	292	(1)
Caller and Callee Preferences	293	(1)
SIP Event Notification Framework: Subscription and Notifications	294	(1)
Subscribe and Notify Methods	294	(1)
Monitoring Registration State Using the Subscription-Notification Framework	295	(1)
SIP Refer Request	296	(1)
Presence and Instant Messaging Overview	297	(1)
SIP Extensions for IM and Presence	298	(1)
Summary	299	(2)
Gateway Control Protocols	301	(20)
MGCP Overview	301	(1)
MGCP Model	302	(1)
Endpoints	302	(1)
Connections	303	(1)
Calls	303	(1)
MGCP Commands and Messages	303	(8)
CreateConnection (CRCX)	304	(1)
ModifyConnection (MDCX)	305	(1)
DeleteConnection (DLCX)	305	(1)
NotificationRequest (RQNT)	305	(3)
Notification (NTFY)	308	(1)
AuditEndpoint (AUEP)	308	(1)
AuditConnection (AUCX)	309	(1)
RestartIn-Progress (RSIP)	309	(1)
EndpointConfiguration (EPCF)	310	(1)
MGCP Response Messages	310	(1)
MGCP Call Flows	311	(4)
Basic MGCP Call Flow	311	(2)
Trunking GW-to-Trunking GW Call Flow	313	(2)
Advanced MGCP Features	315	(2)
Events and Event Packages	315	(1)
Digit Maps	316	(1)
Embedded Notification Requests	316	(1)
Non-IP Bearer Networks	317	(1)
H.248/Megaco	317	(1)
Summary	318	(3)
Part IV VoIP Applications and Services	321	(51)
PSTN and VoIP Interworking	323	(28)
Cisco Packet Telephony	323	(2)
Packet Voice Network Overview	325	(7)
Network Elements	325	(1)
Call Agent: PGW2200	326	(1)
Media Gateway	327	(1)
Service Control Point	328	(1)
Cable Headend	328	(1)
Residential Gateway	328	(1)
H.323/SIP Endpoint/Client	329	(1)
Network Interfaces	329	(1)
Signaling Termination	329	(1)
Inter-PGW2200 Signaling	330	(1)
Connection Control: MGCP	331	(1)
Services Control	331	(1)
PGW2200 Architecture and Operations	332	(5)
PGW2200-Supported Protocols	332	(1)
Execution Environment	333	(1)
North American Numbering Plan	334	(1)
Route Analysis	334	(2)
Digit Analysis	336	(1)
Reroute on Congestion	336	(1)
PGW2200 Implementation	337	(5)
Application Check-Pointing	338	(1)
MGC Node Manager	338	(3)
Accounting	341	(1)
PSTN Signaling Over IP	342	(2)
SCTP	342	(1)
IUA	343	(1)
Changing Landscape of PSTN-IP Interworking	344	(2)
Session Border Controller (SBC)	346	(2)
Summary	348	(3)
Service Provider VoIP Applications and Services	351	(12)
The Service Provider Dilemma	351	(2)
Service Provider Applications and Benefits	353	(1)
Service Provider VoIP Deployment: Vonage	354	(2)
VoIP Operational Advantages	355	(1)
Service Provider Case Study: Prepaid Calling Card	356	(2)
BOWIE.net Multiservice Networks	356	(2)
Session Border Control: Value Addition	358	(1)
VoIP Peering: Top Priority for the Service Providers	359	(1)
Service Provider VoIP and Consumer Fixed Mobile Convergence	359	(2)
Summary	361	(2)
Enterprise Voice over IP Applications and Services	363	(9)
Migrating to VoIP Architecture	363	(1)
Enterprise Voice Applications and Benefits	364	(1)
Advanced Enterprise Applications	365	(4)
Web-Based Collaboration and Conference	366	(1)
The Need for Presence Information	367	(1)
Presence-Aware Services	368	(1)
Wi-Fi-Enabled Phones	369	(1)
Better Voice Quality Using Wideband Codecs	370	(1)
Summary	370	(2)
Index	372