Switching in Ip Networks

by Davie, Bruce S.; Doolan, Paul; Rekhter, Yakov

• ISBN13: 9781558605053
• ISBN10: 1558605053
• Format: Paperback
• Copyright: 1998-05-01
• Publisher: Morgan Kaufmann Pub

Summary

Label switching, an economical and efficient technique for message forwarding in IP networks, is fast becoming a widely deployed solution for improving performance, scalability, and functionality. Written by leading experts in the field, this guide explores the underlying technology of label switching and provides a detailed analysis and comparison of approaches developed by Ipsilon, Cisco, Toshiba, and IBM. It also compares label switching with conventional routing, culminating in a discussion of the Multiprotocol Label Switching (MPLS) standard now being developed by the Internet Engineering Task Force (IETP). This bookthe result of a rigorous review process by key designersis an invaluable resource to network engineers and designers for evaluating the use of label switching in their own networks. * Explains the benefits and limitations of label switching technology * Compares performance, scalability, and robustness of IP Switching, Tag Switching, Cell Switching Router (CSR), and Aggregate Router-based IP Switching (ARIS) * Reveals how label switching simplifies IP over ATM integration problems * Presents the latest snapshot of the MPLS standard, which incorporates the strengths of several of the approaches discussed

Table of Contents

Preface	xi
Chapter 1 Introduction	1	(26)
1.1 How Did We Get Here?	3	(14)
1.1.1 Growth and Evolution of the Internet	4	(2)
1.1.2 Price and Performance	6	(2)
1.1.3 Integration of IP over ATM	8	(6)
1.1.4 Extending Routing Functionality	14	(3)
1.2 A Brief History	17	(7)
1.2.1 IP over ATM	17	(3)
1.2.2 Toshiba's Cell Switching Router (CSR)	20	(1)
1.2.3 IP Switching	21	(1)
1.2.4 Tag Switching	22	(1)
1.2.5 IBM's ARIS	22	(1)
1.2.6 The Multiprotocol Label Switching (MPLS) Working Group	23	(1)
1.3 Summary	24	(1)
Further Reading	25	(2)
Chapter 2 Fundamental Concepts	27	(32)
2.1 Network Layer Routing Functional Components: Control and Forwarding	28	(4)
2.1.1 Forwarding Equivalence Classes	29	(1)
2.1.2 Providing Consistent Routing	30	(2)
2.2 Label Switching: The Forwarding Component	32	(8)
2.2.1 What Is a Label?	32	(1)
2.2.2 Label Switching Forwarding Tables	32	(1)
2.2.3 Carrying a Label in a Packet	33	(1)
2.2.4 Label Switching Forwarding Algorithm	34	(2)
2.2.5 Single Forwarding Algorithm	36	(2)
2.2.6 Forwarding Granularity	38	(1)
2.2.7 Multiprotocol: Both Above and Below	38	(1)
2.2.8 Label Switching Forwarding Component: Summary	39	(1)
2.3 Label Switching: The Control Component	40	(15)
2.3.1 Local Versus Remote Binding	42	(1)
2.3.2 Upstream Versus Downstream Binding	43	(1)
2.3.3 "Free" Labels	44	(1)
2.3.4 Creating and Destroying Label Binding: Control-Driven Versus Data-Driven Label Binding	45	(2)
2.3.5 Distributing Label Binding Information: What Are the Options?	47	(2)
2.3.6 Independent Versus Ordered Creation of Forwarding Entries	49	(2)
2.3.7 Multicast Considerations	51	(1)
2.3.8 Handling Routing Transients	52	(3)
2.4 Edge Devices	55	(1)
2.5 Relationship Between Label Switching and Network Layer Addressing and Routing	56	(1)
2.6 Summary	56	(1)
Further Reading	57	(2)
Chapter 3 The Cell Switching Router (CSR)	59	(24)
3.1 ATM and IP Essentials	60	(9)
3.1.1 Cells, ATM Adaptation Layers, and Virtual Circuits	61	(4)
3.1.2 IP Addresses and Subnets	65	(2)
3.1.3 IP over ATM	67	(2)
3.2 CSR Overview	69	(3)
3.3 FANP (Flow Attribute Notification Protocol)	72	(7)
3.3.1 VCID	75	(1)
3.3.2 FLOWID	76	(1)
3.3.3 PROPOSE/PROPOSE ACK	77	(1)
3.3.4 OFFER/READY	78	(1)
3.3.5 REMOVE/REMOVE ACK	79	(1)
3.3.6 ERROR	79	(1)
3.4 Summary	79	(2)
Further Reading	81	(2)
Chapter 4 IP Switching	83	(34)
4.1 IP Switching Overview	85	(7)
4.2 Ipsilon Flow Management Protocol (IFMP)	92	(15)
4.2.1 IFMP's Adjacency Protocol	93	(1)
4.2.2 IFMP's Redirection Protocol	94	(4)
4.2.3 Encapsulation of Redirected Flows	98	(4)
4.2.4 IFMP and Security	102	(1)
4.2.5 IFMP and TTL	103	(4)
4.3 General Switch Management Protocol (GSMP)	107	(6)
4.3.1 GSMP Adjacency Protocol	109	(1)
4.3.2 GSMP Connection Management Protocol	110	(3)
4.4 Implementations	113	(1)
4.5 Summary	113	(1)
Further Reading	114	(3)
Chapter 5 Tag Switching	117	(38)
5.1 Tag Switching Overview	118	(23)
5.1.1 Support for Destination-Based Routing	119	(8)
5.1.2 Improving Routing Scalability via a Hierarchy of Routing Knowledge	127	(5)
5.1.3 Multicast	132	(5)
5.1.4 RSVP with Tag Switching	137	(1)
5.1.5 Explicit Routes	138	(3)
5.2 Tag Switching over ATM	141	(5)
5.2.1 Carrying Tag Information	141	(1)
5.2.2 Destination-Based Forwarding	142	(4)
5.3 Tag Encapsulation on Non-ATM Links	146	(2)
5.4 Handling Tag Faults	148	(1)
5.5 Handling Forwarding Loops During Routing Transients	149	(2)
5.6 Tag Distribution Protocol (TDP)	151	(2)
5.7 Summary	153	(1)
Further Reading	154	(1)
Chapter 6 Aggregate Route-Based IP Switching (ARIS)	155	(30)
6.1 ARIS Overview	156	(15)
6.1.1 Destination-Based Routing	156	(7)
6.1.2 Distance Vector Routing	163	(1)
6.1.3 Loop Prevention	164	(1)
6.1.4 TTL Adjustment	165	(2)
6.1.5 Behavior During Routing Transients	167	(1)
6.1.6 Additional ARIS Capabilities	168	(3)
6.2 ATM Issues	171	(4)
6.2.1 VP-Merge	172	(1)
6.2.2 Non-Merging Switches	173	(2)
6.3 Label Encapsulation	175	(3)
6.4 The ARIS Protocol	178	(3)
6.4.1 Protocol Structure	179	(1)
6.4.2 Protocol Operation	180	(1)
6.5 Summary	181	(2)
Further Reading	183	(2)
Chapter 7 Comparison of Label Switching Approaches	185	(34)
7.1 Taxonomy	186	(1)
7.2 Control-Driven Versus Data-Driven Approaches	187	(12)
7.2.1 Performance	188	(5)
7.2.2 Scalability	193	(3)
7.2.3 Robustness	196	(1)
7.2.4 Soft and Hard State	197	(1)
7.2.5 Host Support	198	(1)
7.3 Data-Driven Approaches	199	(1)
7.4 Control-Driven Approaches	200	(11)
7.4.1 Loop Prevention and Mitigation	200	(3)
7.4.2 Ordered Versus Independent Binding	203	(2)
7.4.3 Label Distribution Protocol Issues	205	(3)
7.4.4 Support for Hierarchy	208	(2)
7.4.5 Encapsulations	210	(1)
7.5 Label Switching or Conventional Routing?	211	(3)
7.5.1 Functionality	213	(1)
7.5.2 Scalability	213	(1)
7.5.3 IP/ATM Integration	214	(1)
7.5.4 Evolvability	214	(1)
7.6 Label Switching Versus MPOA	214	(2)
7.7 Summary	216	(2)
Further Reading	218	(1)
Chapter 8 Multiprotocol Label Switching (MPLS)	219	(14)
8.1 The MPLS Working Group	220	(3)
8.1.1 Origins and Charter	220	(1)
8.1.2 Description of Working Group	220	(2)
8.1.3 Goals and Milestones	222	(1)
8.2 The MPLS Framework	223	(1)
8.3 The MPLS Architecture	224	(2)
8.4 The Label Distribution Protocol (LDP)	226	(2)
8.5 Open Issues	228	(3)
8.5.1 Looping	228	(1)
8.5.2 Local Versus Egress Control	229	(1)
8.5.3 Label Distribution Issues	230	(1)
8.6 Summary	231	(1)
Further Reading	232	(1)
Bibliography	233	(2)
Glossary	235	(6)
Index	241