Services
 

Gigabit Switch IC

Multi-protocol Switch Router (MPR)-Differentiated Service (DiffServ)
Technology Territory Broadband
Technology Brief The networking applications are getting diversified; users needs different Quality of Services.For example: on-line talking needs the real-time interaction, the videos or MP3 download needs more bandwidth.ICL's "Multi-protocol Switch Router-DiffServ" could support the bandwidth control, prioritization & allocation. It would be more effective to utilize the network resources. There're two versions for CCL's DiffServ solution: software version on Linux & Network Processor (NP) version.
Application
  • Linux Version is a software solution which could be used in PC or SOHO equipment, ex: Cable Modem, ADSL Router…etc.
  • There are high speed DiffServ & Layer 3 IP routing functions in Network Processor Version. It is for the application in Enterprise Network Environment.
Specification
  • Packet Classification
    • Multi-Field Classification for 512 policy rules based on
      • Destination IP/Port; Source IP/Port; Protocol ID; DS codepoint
    • Specify a range of the field: Low < Value < High
      • FTP: 20<Port<22 (Port=21)
      • Subnet: 140.95.255.255<IP<140.97.0.0 (140.96.0.0/16)
    • Bandwidth (BW) regulation per policy rule: Byte/sec
      • Excessive traffic marked as "out-of-profile"
    • Packet flows matched with policy rules are mapped into EF, AF1, AF2, AF3, AF4 classes
    • Unmatched packet flows are mapped to BE class
  • Queueing and Discarding
    • Out-of-profile packets of EF class are discarded
    • Packets of AF classes are discarded by RIO algorithm
      • Random Early Discard (RED) for in- and out-of-profile
      • When average queue length (QL_avg)<min, no discarding
      • When QL_avg>max, 100% discarding
      • When min< QL_avg<max, drop % monotonically increase to Pmax
    • QL_avg is defined as average queue length of
      • ONLY buffered in-profile packets counted for arriving in-profile packet
      • ALL buffered packets counted for arriving out-of-profile packet
  • Scheduling
    • A packet flows is assigned to a “Class” according to the matched policy rule
      • EF: Explicit Forwarding, for mission-critical real-time traffic
      • AF1~AF4: Assured Forwarding, for applications with different QoS (delay/loss) requirements:
        • Different queue length thresholds (min_in, max_in, min_out, max_out) provides different discarding behavior among AF classes
      • BE: Best Effort, as in today's Internet
  • Scheduling algorithms allocate bandwidth among classes
    • Self Clocked Fair Queueing among all four AF classes
    • Deficit Round Robin among EF, AF, and BE
Selling Points
  • Support two matching models: Exact & Range. It can reduce the waste from extending from single matching to multi-matching.
  • Support two classification algorithms
    • Linear search: with better performance and less memory requirement when the rules are less than 10.
    • Parallel search: with efficient classification due to support logarithmic complexity.
  • IP Routing in Network Processor Version can support CIDR (classless inter-domain routing)
  • Linux OS is from open source, without the high royalty charge. It can also support different CPUsand be integrated with other open source to support multiple functions.
  • Network Processor has the advantages of high performance and programmable flexibil.
    • Customers can upgrade the functions based on different requirement.
Suggested Licensee
  • For Linux Version: who understands Linux kernel & NIC Driver
  • For Network Processor Version: who understands Intel IXP-1200 NP
  • RFC 2474:"Definition of the Differentiated Services Field(DS field) in the IPv4 and IPv6 Headers" , 1998/12
Reference
  • RFC 2475 :“An Architecture for Differentiated Services”, 1998/12
  • RFC 2597 :“Assured Forwarding PHB Group”,1999/6
  • RFC 2598 :“An Expedited Forwarding PHB”,1999/6
Name: Sandra Chiu
Communication & Visual Technology Marketing Department
Tel: +886-3-5917628
Fax: +886-3-5820240
E-mail: SandraChiu@itri.org.tw