Stein-64 Slide 1

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VCCVextensions

• PWE3 64th IETF
• 10 November 2005

Yaakov (J) Stein
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2 PW OAM methods
original TDMoIP OAM 1 OAM PW per PSN
tunnel assume defects/performance are the same
for all PWs in tunnel
VCCV style OAM OAM packets in each PW higher
overhead (BW) when there are many PWs in tunnel
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Performance Measurement

• VCCV presently provides only connectivity
  verification
• full PW OAM should also provide measurements of
• one way and round trip delay
• PDV ( distribution? spectrum?)
• packet loss ratio
• for TDM PWs it is also useful to
• monitor backup PWs for fast switch-over
• maintain clock synchronization for multiple TDM
  PWs
• CW format
• use PWACH

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PW Performance OAM format
PWACH
VERSION
RESERVED
need IANA allocation
0001 0000 00000000 associated
channel type
type code
service specific info
timestamps
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Open questions

• what should the time format be?
• RTP style 32 bit based on N8KHz
• NTP style seconds expressed as 32 bit integer
  32 bit fraction
• ICMP style 32 bit milliseconds
• IEEE 1588 style 32 bit seconds 32 bit
  nanoseconds
• how many timestamps?
• 1 for approximate round-trip
• 2 for approximate one-way
• 3 for round-trip with D t
• 4 for ICMP-like timestamps
• many for IEEE 1588-like timestamps
• what about loop-back requests?