Tux and the Five Nines

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Tux and the Five Nines
Noor Ul Mubeen Wipro Technologies Ltd.
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What is Five 9's in Telecom

• Percentage Uptime of a Telecom node.
• 99.999 a.k.a five 9's.
• In terms of downtime
• Five 9's lt-gt 5 min downtime/year
• Six 9's lt-gt 32 sec downtime/year
• Its also a System engineering benchmark for
  building blocks.
• E.g. To measure sched latency consider the delay
  value for 99.999 area under sched latency
  Histograph.

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What is Five 9's in Telecom...

• Such 'Carrier Grade' Guidelines imposed by
  Telecom regulatory bodies on Service/ Network
  providers.
• E.g. Telecom Regulators - TRAI, FCC.
• E.g. Guidelines OSSGR, NEBS
• Quite frequently a marketing persons sales-pitch.
  
• So insist on long-duration 'field reports' as
  proof.
• Five Nines is nothing new in Telecom, but
  (relatively) Linux is.

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Linux influence in Telecom

• Platform support
• Industry platform freedom cPCI, ATCA..
• Multiple ArchPPC,x86,MIPS,ARM 64bit support
• HPI watchdog, OpenIPMI
• OS support
• Freedom to customise(GPL). Not tied to s/w
  vendor.
• SMP and HyperThreading
• Easy Cross compilers, toolchain
• Improved performance RT patches, O(1) const
  order scheduler, preemption in 2.6
• Protocol Stack support
• Robust TCP/IP stack. Ipv6, Ipsec, MIPv6
• SIGTRAN SCTP, M2UA/M3UA, TIPC and RTP stacks.

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Cone of Telecom Evolution
Software
Proprietary
Open Source
VoIP
TDM
Switching
Hardware
COTS
In-House
Closed Hybrid Open phase phase
phasee
The narrowing distance between software, hardware
switching axes, signify affinity/interoperabilit
y. A cone, rather than pyramid implies there are
possibly other axes (e.g. Standards) .
Time --gt
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Open Source Development Labs

• Org formed in 2000 to create roadmap for Linux in
  industry (www.osdl.org)
• OSDL founder members IBM,HP,CA,Intel NEC.
• Linus Traovalds moves from Transmeta to OSDL
  (2001). Andrew Morton joins-in.
• OSDL chapters include
• Desktop Linux
• Data center Linux(Enterprise)
• Carrier Grade Linux CGL lt
• Mobile Linux

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Open Source Development Labs

• CGL defines a set of requirements specifications.
  Current version V3.1
• CGL specification categories
• 1) Hardware
• E.g. Blade HotSwap msg, shutdown from Shelf Mgmt
• 2) Availability
• E.g. Live patching, Fast boot, POSIX mutex
• 3) Clustering
• E.g. AIS checkpointing API, Application failover.

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Open Source Development Labs...

• 4) Performance
• E.g. Low sched latency 1ms, high res timers
• 5) Serviceability
• E.g. Kernel Panic enhancements, persistent dev
  naming.
• 6) Security
• E.g. Ipsec for Ipv4/6, password integrity
  checking.
• 7) Standards
• E.g. LSB 2.0.1,POSIX, RFC compliant stacks

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CGL,Middleware, SA Forum APIs
E.g.MGC, SIP server
(AIS)
Ais
(HPI)
CGL
(You are Here)
E.g. cPCI or ATCA based

• Commercial CGL based distributions include
  MontaVista(CGE), WindRiver(NPE), TimeSys etc.

Figure SourceThe Service Availability Forum
Platform Interface
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CGL spec the other facts

• CGL specifications are still maturing
• E.g. Security requirements only in v3.1
• Not as stringent as the legacy telecom
  requirements.
• E.g. kernel space Live patch is yet to evolve,
  whilst run-time patching is a 'must' requirement
  in telecom.
• Slightly biased towards existing sourceforge
  implementations rather than being generic
  requirements.
• E.g. 'serel' for FastBoot option.

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References related links

• www.osdl.org
• www.picmg.org
• www.mvista.com
• www.windriver.com
• www.saforum.org
• www.linuxbase.org

RT scheduling analysis lthttp//www.linuxdevices
.com/files/article027/rh-rtpaper.pdfgt Telecom
regulators lthttp//www.telecomsportal.com/
linksregs.htmlgt Equipment reliability
lthttp//assist.daps.dla.mil/quicksearch/basic
profile.cfm?ident number53939gt
Any TradeMarks in above slides are Registered to
respective companies.
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References related links
Email Noor . Mubeen _at_ wipro .com