ONT Notes – Pre-classify and End-to-end QoS

  • VPNs (Didn’t ISCW cover this?)
    • Provide
      • Confidentiality
      • Integrity
      • Authentication
    • Types
      • Remote-access
        • Client-initiated
        • NAS-initiated
      • Site-to-site
        • LAN-to-LAN
        • Extranet
  • L3 Tunneling protocols
    • GRE
    • IPSec
  • Pre-classify allows traffic to be classified before being sent across a tunnel or crypto-ed.
    • qos pre-classify
    • Provides a view into the original IP headers
    • To classify on pre-tunnel header, apply the policy to the tunnel interface WITHOUT pre-classify.
    • To classify on post-tunnel header, apply the policy to the physical interface WITHOUT pre-classify.
    • To classify on pre-tunnel header, apply the policy to the physical interface WITH pre-classify.
  • SLA – agreement with provider to guarantee QoS mechanisms across their network based on your markings.
    • Assures availability, loss, throughput, delay, and jitter.
  • End-to-end QoS
    • To be effective, each hop in the path must have QoS configured similarly.
    • Necessary in three locations
      • Campus – within the customer network
      • The edges – customer facing the provider, provider facing customer
      • On the provider network
  • QoS tasks
    • Campus access switches
      • Speed/duplex settings
      • Classification
      • Trust
      • Phone/access switch configs
      • Multiple queues on switch ports, including priority for VOIP
    • Campus distribution
      • L3 policing and marking
      • Multiple queues on switch ports, including priority for VOIP
      • WRED
    • WAN edge
      • SLA definitions
      • LLQ
      • LFI
      • WRED
      • Shaping
    • Provider cloud
      • Capacity planning
      • PHB
      • LLQ
      • WRED
  • Enterprise campus QoS implementation
    • Implement multiple queues to avoid congestion
    • Assign VOIP and video to highest priority queue
    • Esablish trust boundaries
    • Use policing to rate-limit excess traffic
    • Use hardware QoS when possible
  • Control Plane Policing (CoPP)
    • Applies QoS policy to traffic destined for the router
      • Routing protocols
      • Management protocols
    • Can be used to avoid DOS attacks
    • Applied to control-plane in global config

Aaron Conaway

I shake my head around sometimes and see what falls out. That's what lands on these pages. If you have any questions, the best way to contact me is through Twitter at @aconaway.

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2 comments for “ONT Notes – Pre-classify and End-to-end QoS

  1. February 4, 2010 at 12:37 pm

    love the new site theme and can’t wait for my ONT studies, you are doing a great job and I’m sure gonna use it!

    Rofi

  2. February 4, 2010 at 9:27 pm

    Thanks, Rofi. Be sure to get your ONT done by July 31st to get credit for it towards your CCNP!

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