Design of QoS Router Terrance Lee

Broadband Internet Architecture Intelligent Access Electronic Switch (Intserv or Diffserv) Switching /Routing QoS Security Core Network Access Network Optimized for speed Packet over Sonet (Diffserv) (IP/PPP/Sonet/DWDM) All Optical Network (MPLS) Access Network Access Network Access Network  Content Provider

Core Network Optical Switch Cache Server for Content Providers Label Distribution Traffic Engineering

Access Network Cache Server for Content Providers QoS Router - Control Plane QoS Routing RSVP Admission Control - Data Plane QoS Mechanisms Measurements Switch Fabric - Management Plane QoS Service Management

Admission Control Bandwidth allocation in access networks Heavily depends on the adopted service scheduling algorithm (e.g., WFQ, Rate Monotonic) Trade off between complexity and utilization

QoS Mechanisms Packet Classifier Meter Marker Dropper Queue Manager Shaper Scheduler

PHYPHY MACMAC Frame Engine Packet Classifier Search Engine Meter Marker Dropper Queue Manager Shaper/Scheduler Memory Modifier HeaderPayload TTL FCS Protocol Conversion Compression Authentication Encryption Memory RSVPQoS RoutingAdmission Control Network Planning Management Control Data Switch Fabric or MAC QoS Measurement QoS Service Management

Packet Classifier Purposes - QoS Guarantee - Security - Billing - etc.

Packet Classifier Behavior Aggregate IPv4 Multi-Field-5 IPv4-Multi-Field-6 IEEE 802 MAC IEEE 802.1p IEEE 802.1q IPv6 Multi-Field-5 IPv6 Multi-Field-6 Free Form

Packet Classifier Hash Bucket 64 Rules Src and Dest IP Addresses: Prefix Match Src and Dest Port Numbers: Range Match Protocol ID: Exact Match 20 Bytes/Rule (Include Valid Time Period and Output) Memory Size: ~ 4K Bytes Wire Speed Classification: ~ 5 Mpps (32-bit 100MHz) (4 Reads)

Meter Average Rate Meter Parameters: average rate, delta interval EWMA Meter Parameters: average rate, delta interval, gain Token Bucket Meter (srTCM, trTCM) Parameters: CIR, PIR, CBS, PBS, EBS

Meter 64 Token Bucket Entries Memory Size: ~ 256Bytes Stored Parameters: Bucket Size, Bucket Occupancy, Leaky Rate, Scaling Factor Wire Speed Metering: ~ 5 Mpps (32-bit (3 Reads, 1 Write)

Marker An Optional Service When TRUE, Remark the Attribute Field for All Traffic When FALSE, Remark Only Unmarked Traffic Attribute Field TOS Byte DSCP Field IEEE 802.1p Priority Field Proprietary (User Defined)

Marker 4 Priority Queues 3 Levels of Drop Precedence

Dropper Drop from Head Drop from Tail RED WRED FRED Always Drop User Defined

Criteria for Dropping Queue Threshold Arrival Rate Other

Drop Metric IP Precedence DSCP Value IEEE 802.1p Priority Value RSVP Session Queue Depth Packet Arrival Rate Other

Scheduler FIFO (First In First Out) SP (Strict Priority) WFQ (Weighted Fair Queuing) SP/WFQ WRR (Weighted Round Robin) Priority Bandwidth (Priority with Maximum Burst Constraint)

Scheduler Configurable Number of Queues under Strict Priority Weights of WFQ: 0-63 Up to 4 Queues

Shaper An Optional Service Per-Class Token Bucket Traffic Shaping srTC and trTC shaping SLA Guarantee When Enabled, Service Becomes Non-Work-Conserving

Summary We Prototyped a Router with Complete QoS Mechanisms Future Work: IPSec, MPLS Capability