Routers, switches, and transmission equipment form the backbone of the Internet, yet many users and service technicians do not understand how these nodes really work.
Advanced Router Architectures addresses how components of advanced routers work together and how they are integrated with each other. This book provides the background behind why these building blocks perform certain functions, and how the function is implemented in general use. It offers an introduction to the subject matter that is intended to trigger deeper interest from the reader. The book explains, for example, why traffic management may be important in certain applications, what the traffic manager does, and how it connects to the rest of the router. The author also examines the implications of the introduction or omission of a traffic manager into an advanced router. The text offers a similar analysis for other router topics such as QOS and policy enforcement, security processing (including DoS/DDoS), and more.
This book covers which mandatory and which optional building blocks can be found in an advanced router, and how these building blocks operate in conjunction to ensure that the Internet performs as expected.
Internet Topology Change
Overview
Current Status
Traffic and Traffic Growth
The Carrier Business Model
Overview
Service Level Agreements (SLAs)
The VoIP Business Model
Internal Corporate Accounting
Advanced Routers in Central Office Applications
Overview
Central Office (CO) Colocation
Function Split
Overview
Traditional System Partitioning and Function Split
Functions within the Port Card
Functions within the Processor Card
Functions within the Switch Card
Functions within the OAM&P Card
High Availability
Overview
Definition
Implications
Network View of Redundancy and Failsafe Operation
Example
Design Life Time and Single Point of Failure Impact
Definition of Availability
1+1 Redundancy
1:1 Redundancy
2 out of 3 (or N out of N+1) Redundancy
Redundant Switch Fabric Cards
Redundant Line Cards
Redundant Links
Redundant Power Supplies
Software Robustness
OAM&P Control over Redundant Subsystems
Timed Switchover
Switchover on Demand
Reducing Human Error Probability
The Chassis
Overview
Single-board versus Modular Designs
Line Cards
Overview
Definitions
Functional Requirements
Further Impact of Advanced Router Architectures
Differentiation of Functions
Line Card Implementation in Single-board Designs
Line Card Implementation in Midplane Designs
Line Card Implementation in Backplane Designs
Line Card Messaging and Communications
Interior and Exterior Border Gateway Protocols
Line Card Functions for PSTN Internetworking
Port Card Functions
Network Processor and Traffic Manager Software Implications Local Control Processors for Line or Processor Cards
Switch Fabric Cards
Overview
Functional Requirements for an Advanced Router's Core
History of Router-internal Interconnects
Basics
Crosspoint Switches and Crossbar Switches
Shared Memory Switches
Non-buffered, Non-queued Switch Fabrics
Buffered and Queued Switch Fabrics
Combined Virtually Output Queued Switch Fabrics
Metrics of Switch Fabrics
Net Bit Rate or Link Rate Utilization (Minimum, Maximum, Average)
Throughput (Total and on a per-Link Basis)
System Availability (Minimum)
System Uptime (Minimum)
Reliability (Error Rate)
Logical Connection Setup Time (Minimum, Maximum, Average)
Logical Connection Teardown Time (Minimum, Maximum, Average)
Delay and Latency
Round-Trip Delay (Minimum, Maximum, Average)
Cell Delay Variation (CDV) (Minimum, Maximum, Average)
Scalability
Field Upgradability
Resource Utilization on the Network Processor
Cost Structure
Feasibility
Performance Extension
Alternative Solutions
The "Switchless Switch"
Multicast and Broadcast
Bandwidth Overprovisioning
Traffic Manager Functions versus Queue Manager Functions
Deterministic Behavior
Switch Fabric I/O
Software Function Set in Local Switch Fabric Control
Operation, Administration, Maintenance and Provisioning
Overview
Definition of OAMP
Functions of the OAM&P Entity
Operational Statuses
Status Transitions
Relationship with NMC
Implementation
Fail-safe and Fault-tolerant OAM&P Entity Operation
OAM&P Entity Internal Communication
Examples of Failure Modes of Managed Entities
The Necessity for the Device-Global View
Sample OAM&P Card Schematic .
Biography
Kloth, Axel K.