WAN Basics Tsunami MP'11 QB'11 QuickBridge 60250 Tsunami MP'11 Quality of Service

1
WAN Basics Tsunami MP.11 - QB.11 QuickBridge
60250 Tsunami MP.11 Quality of Service
April 2008
2
Introduction

• Software Release v2.3 introduced QoS capabilities
  for the Tsunami MP.11 Family
• All models except the Tsunami-2411 and QB-2411
  support this feature
• Based on 802.16 (Wimax) QoS scheme/definitions
• Real Time Polling Service
• Best Effort
• Useful for VoIP, Video Streaming (real time
  applications)

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General Concept

• First Step
• Create rules to inspect and identify packets
  according to certain criteria (Packet
  Identification Rules)
• Create different sets of parameters that will
  determine how a stream of application data will
  be treated (Service Flow Classes)
• Second Step
• Create QoS Classes or Policies by combining PIRs
  with SFC
• Final Step
• Apply a QoS Class/policy to each SU

• PacketIdentificationRules
• aaa
• bbb
• ccc

• ServiceFlowClasses
• xxx
• yyy
• zzz

QoS Classes QoS 1 PIR aaa ltgtSFC yyy PIR ccc
ltgt SFC xxx QoS 2 PIR bbb lt-gt SFC xxx
QoS lt-gt SU QoS 1 gt SU 2 QoS 2 gt SU3 and SU4
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General Concept (continued)

• All QoS configuration is done at the BSU
• No option to enable or configure at the SU/RSU
• You can not disable QoS
• As soon as you load v2.3, QoS is active and all
  SUs go to Unlimited Best Effort Class of
  Service (this is one of the QoS Classes that come
  pre-defined by default and can not be deleted)

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Definitions and Terminology

• Packet Identification Elements (Identifiers)
• 11 identifiers
• Packet Identification Rules (PIR)
• Up to 64 PIRs per BSU 17 come predefined
• Service Flow Classes (SFC)
• Up to 32 service flows per BSU 7 predefined
• QoS Classes
• Up to 8 QoS Classes per BSU 4 come predefined
• Up to 8 SFCs per QoS class
• Up to 8 PIRs can be associated to each Service
  Flow

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Packet Identification Elements

• Also called Packet Identifiers
• Are specific fields/elements in the frame/packet
  that can be inspected by the MP.11 system in
  order to make QoS decisions
• There are 11 Packet Identifiers that an MP.11 can
  look into
• Source MAC address
• Destination MAC address
• Ether type
• Ether Priority (802.1p tag)
• VLAN ID
• Protocol ID
• IP ToS (Layer 3 identification)
• Source IP address
• Destination IP address
• Source port
• Destination port
• Packet Identifiers come pre-defined and can not
  be changed

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Packet Identification Elements

• Layer 2 Identifiers
• Layer 3 Identifiers
• Layer 4 Identifiers Destination and Source
  port number

Preamble and SOFD (Start of Frame Delimiter) not
shown
802.3 Frame with 1Q extension
IPv4 Packet
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Packet Identification Rules

• PIR are sets/combinations of Packet Identifiers
  with associated values or ranges
• MP.11 system will analyze the packets and compare
  them against these rules
• There are 17 Rules that come pre-defined
• You can add more rules, up to a maximum of 64 per
  BSU

Click here to add your own PIR
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Adding a PIR

• Before we can add a PIR we must investigate and
  answer the following questions
• How do we identify the packets?
• What common denominators will those packets have?
• Will they have a common destination port?
• Will they have a unique source IP address?
• Will they have a specific VLAN ID?
• Once we determined this we just click Add Table
  Entries and create a new PIR entering the values
  in the following table

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Service Flow Class

• Defines characteristics of a communication link
• Support two scheduling types
• Best Effort (BE)
• Real time Polling Service (rtPs)
• Service Flow Direction
• Uplink, Downlink
• Maximum sustained data rate (MIR)
• Minimum reserved traffic rate (CIR)
• Maximum Latency
• 5..100ms in steps of 5ms
• Tolerable Jitter
• 0..100ms in steps of 5ms
• Traffic priority
• 0..7 with 0 as the lowest and 7 as the highest
  priority

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Service Flow Class
These are the 7 predefined Service Flow Classes
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Latency and Jitter

• Latency is packet transmission delay between Tx
  at one end and Rx at the other end
• Jitter is latency variation
• If latency 50 and jitter 10, then packet will
  arrive between 40 and 50 ms

P1
P2
Tx
Rx
Latency 1
Latency 2
P
Tx
Rx
Jitter
Latency
13
Polling Timer

• BSU poll each SU on a regular interval the
  polling timer
• The polling timer can be 1, 2, 5, 10, 20 or 30 ms
• It depends on latency (at least 3 poll per
  latency period)
• Latency 20 ms requires 1 poll every 6,6 ms,
  then polling timer 5 ms
• It depends on CIR (enough poll to provide the
  committed throughput)
• CIR 4 Mbps means 500000/2304 217 superframe
  per second
• 217 SFps requires 1 poll every 4,6 ms then
  polling timer 2 ms

Poll
Data
Poll
Data
Poll
Data
Poll
Data
BSU
SU
Polling Timer
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Polling Timer effect on Ping

• Ping request can only be transmit with polling
  packet
• SU immediately reply to poll with data
• Ping reply has to wait until the next polling
  packet
• The minimum Ping round trip is 2 polling timer (
  processing time)
• Since minimum polling timer 1 ms then minimum
  ping round trip gt 2 ms (usually 3 to 4 ms)

Ping req
Ping rep
Poll
Data
Poll
Data
Poll
Data
Poll
Data
BSU
SU
Ping req
Ping rep
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Service Flow Priority

• Static Priority
• Each Service Flow is assigned
• A scheduling type (BE or RTPS)
• A traffic priority (0 to 7)
• RTPS service flows always get higher priority
  than BE ones
• Dynamic Priority
• In order to comply with CIR needs, Service Flow
  dynamically change priority level
• Dynamic priority is based on a 200 ms period
• If a BE service flow get 2 Mbps CIR (400 Kbits
  over 200 ms), it is promote to high priority
  status as long as it did not reach the 400 Kbits
  traffic limit during that 200 ms period, then it
  goes back to low priority for the remaining of
  the period

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QoS Class

• Defines correlation between SFC and PIRs
• A QoS class is defined by
• QoS Class Name
• Up to 4 SFC
• Up to 8 PIRs associated to each SFC
• PIR Priority
• Defines the order of execution of PIR during
  packet identification process
• 0..63, 0 being lowest priority (executed last)
• Within a QoS class, a PIR must be assigned to
  only one SFC in given direction
• This is to avoid ambiguity, so that when a packet
  arrives and is inspected and falls in a given
  PIR, then it can only be assigned to one SFC

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QoS Class Table
These are the 4 predefined QoS Classes
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QoS SU Association

• This is done at the QoS-SU Table
• Up to 250 entries
• Each SU wireless MAC can be assigned to only
  one QoS Class
• All non QoS SUs will default to the predefined
  Unlimited Best Effort QoS class which is at
  index 1
• Changes take effect immediately

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QoS Example

• How do you configure a 5054 BSU-SU link to allow
  for 10 G729 VoIP calls Best Effort traffic?

BSU
SU1
Internet