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Avaya Aura Five Nines by PacketBase
 

Avaya Aura Five Nines by PacketBase

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Avaya offers a variety of communication software, servers, gateways and availability features to meet the needs of small, midsize and large enterprises. Avaya can architect a “Five Nines” (99.999% ...

Avaya offers a variety of communication software, servers, gateways and availability features to meet the needs of small, midsize and large enterprises. Avaya can architect a “Five Nines” (99.999% availability) or better solution for any customer at highly competitive price points
Some vendors have different perspectives as to what Five Nines means and how it may be achieved. This document aims to dispel some misconceptions in the market and show how Avaya achieves Five Nines across a range of customer scenarios.
-PacketBase.com

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    Avaya Aura Five Nines by PacketBase Avaya Aura Five Nines by PacketBase Presentation Transcript

    • Achieving Better than Five Nines Availability with Avaya Aura ™ Bahareh Momken PhD, Avaya Labs Robert McMaher MST, WW Technical Operations Mark Kelsey, UC Product & Solutions Marketing PacketBase, Inc. www.packetbase.com
    • Agenda  Introduction  Advantages of Avaya Reliable Software  Availability Measures and Solutions  Midsize Enterprise Solution Case Studies  Large Enterprise Solution Case Studies  Methodology and Assumptions – Notes on Availability Calculations (including Branch) – LAN/WAN Design for High Availability – Reliable Software Design Principles For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 2
    • Introduction  Avaya offers a variety of communication software, servers, gateways and availability features to meet the needs of small, midsize and large enterprises  Avaya can architect a “Five Nines” (99.999% availability) or better solution for any customer at highly competitive price points  Some vendors have different perspectives as to what Five Nines means and how it may be achieved  This document aims to dispel some misconceptions in the market and show how Avaya achieves Five Nines across a range of customer scenarios For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 3
    • Advantages of Avaya Reliable Software  Architected with a modular design and functional independence to avoid complexity  Built from existing designs with documentable quality wherever possible  Built-in system monitoring, failure detection, logging and recovery mechanisms  Software quality checks and reliability predictions at every stage of development, system test and product introduction  Followed by periodic software availability assessments to monitor and analyze data from the field For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 4
    • Availability Measures and Solutions System Calculated Typical Solution Characteristics Availability Downtime per Year 99.999+% < 5 minutes Global geo-redundant, PSTN fall back, Processor > Five Nines Ethernet duplication, redundant customer LAN/WAN, clustered gateways (not remote) with Local Survivable Processor (LSP) or Enterprise Survivable Server (ESS), redundant servers and switches 99.999% 5 minutes Redundant customer LAN/WAN, remote clustered Five Nines gateways with LSP or ESS, redundant servers 99.99% 53 minutes Reliable customer LAN, simplex WAN, single gateway Four Nines with LSP or Standard Local Survivable (SLS), non- redundant servers 99.9% 9 hours Non-reliable customer LAN/WAN susceptible to frequent Three Nines failure and congestion For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 5
    • Achieving Better than Five Nines Availability with Avaya Aura™ Midsize Enterprise Solutions (up to 450 endpoints) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 6
    • Single Site Midsize Enterprise Solution (up to 450 endpoints) With Better than Five Nines Availability Main Site > 5-9s availability S8300 as Primary Server S8300 as LSP  Avaya Aura Communication Manager (CM) on S8300 main with S8300 LSP supported in H.248 gateways with redundant power supply  S8300/S8300 Local Survivable Processor (LSP) provides: Redundant Customer LAN – Alternate gatekeeper for phones and gateways – Connection preserving failover (stable calls survive during failover) – Cluster of gateways providing PSTN N+1 DSP resources and ISDN T1/E1 trunks Source: Avaya Labs For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 7
    • Multi Site Midsize Enterprise Solution with Simplex Wide Area Network (up to 450 endpoints) S8300 as Primary Server S8300 as LSP Main Site > 5-9s availability Redundant Customer LAN WAN/Internet Simplex Remote Site ≥ 4-9s availability PSTN  Communication Manager on Standard Local Survivable (SLS) or S8300 with LSP  Simplex WAN link to branch is subject to failure SLS or S8300 LSP  Local stable calls survive during failover, calls over WAN will fail  When failover is complete, calls over WAN will fall back over PSTN PSTN For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 8
    • Multi Site Midsize Enterprise Solution with Redundant Wide Area Network (up to 450 endpoints) With Better than Five Nines Availability Main Site > 5-9s availability Remote Site = 5-9s availability  Redundant WAN link improves site availability  LSP in branch + cluster of gateways  Local stable calls survive during failover, calls over WAN will fail (but redundant WAN reduces failures) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 9
    • Midsize Enterprise Case Study S8300/S8300 LSP Availability Calculation - Main Site S8300 primary server supported in H.248 gateway with redundant power 99.995% S8300 as LSP supported in H.248 gateway with redundant power 99.995% Redundant Customer LAN 99.9999% Time to complete failover* < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.9997% Power/Environmental availability x 99.99955% Availability for S8300/S8300 LSP Solution at Main Site = 99.9992% *Failover is connection preserving, so stable calls survive Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data ( 2,200+ system years per quarter) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 10
    • Midsize Enterprise Case Study Availability Assumptions (1 of 2)  Gateway and IP phone failover to LSP is connection preserving (stable calls survive during failover) for all calls. The 3 minutes of down time (which includes failure detection, failover, gateway reset by LSP and phone re- registration) is experienced by small percentage of users and depends on the call rate.  IP-phones TCP keep alive interval default value is 5 seconds with administrable count with default being 5. Phones will discover that they have lost the signaling channel within 25 to 45 seconds of the actual outage (the default is 20 sec with 5 retransmissions at 5 sec intervals).  The H.248 gateways send keep alive signals to Avaya Aura Communication Manager (CM) every 15 seconds with a failure threshold of 3 times. CM sends keep alive to the gateway every 20 seconds.  Up to 30 alternate gatekeepers are available for the IP-phones and up to 4 for the H.248 gateway.  The cluster of H.248 gateways provide N+1 DSP resources and can administer trunk groups in N+1 T1/E1 resources in order to provide service in active/active mode (parallel).* *Note: Gateways must be in connecting network regions in order to share DSP resources and ISDN trunks For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 11
    • Midsize Enterprise Case Study Availability Assumptions (2 of 2)  A single G450 Gateway with the option of redundant power supply (hot swap FRU) has an availability value > 99.995%.  Avaya Aura Communication Manager is supported on S8300 equipped with Solid State Drive (SSD) and Hard Drive partitioning.  450 IP phone re-registration to Processor Ethernet (PE) of S8300 < 1 minute.  Gateway reset by new active server < 1 minute.  Time to Service (TTS) phones and Short Network Outage: TTS enabled IP- phones do not lose registration to the primary server and are back in service immediately after the network heals.  Standard Local Survivable (SLS) feature on H.248 gateways: with this feature the gateway itself contains basic call control ability if the connection to the main server is lost.  Inter Gateway Alternate Routing (IGAR) provides an alternate means of bearer connection between gateways when IP-WAN is incapable of carrying the bearer traffic.  PSTN fall back capabilities in the event of WAN outages. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 12
    • Achieving Better than Five Nines Availability with Avaya Aura™ Midsize Enterprise Solutions (up to 2,400 endpoints) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 13
    • Single Site Midsize Enterprise Solution (up to 2,400 endpoints) With Better than Five Nines Availability Main Site > 5-9s availability S8800 Primary Server S8800 as LSP  Avaya Aura Communication Manager (CM) on S8800 main with S8800 LSP & redundant power supporting a cluster of G450 Gateways  S8800/S8800 LSP provides: Redundant Customer LAN – Alternate gatekeeper for phones and the gateways – Connection preserving failover (stable calls survive during failover) – Failure detection + complete failover to LSP < 3 minutes – Cluster of gateways providing N+1 DSP resources and ISDN T1/E1 trunks PSTN Source: Avaya Labs For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 14
    • Multi Site Midsize Enterprise Solution (up to 2,400 endpoints) Main Site > 5-9s availability Remote Site ≥ 4-9s availability  Communication Manager with SLS, S8300 LSP or S8800 LSP  Simplex WAN link to branch is subject to failure  Local stable calls survive during failover, calls over WAN will fail  When failover is complete, calls over WAN will fall back over PSTN For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 15
    • Multi Site Midsize Enterprise Solution with Redundant Wide Area Network (up to 2,400 endpoints) With Better than Five Nines Availability Main Site > 5-9s availability Remote Site = 5-9s availability  Redundant WAN link improves site availability  LSP in branch + cluster of gateways  Local stable calls survive during failover  Calls over WAN will fail (but redundant WAN reduces failures) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 16
    • Midsize Enterprise Case Study S8800/S8800 LSP Availability Calculation - Main Site S8800 primary server with redundant power 99.996% S8800 as LSP with redundant power 99.996% Cluster of G450 Gateways > 99.9999% Redundant Customer LAN 99.9999% Time to complete failover* < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model 99.9998% Power/Environmental availability x 99.99955% Availability for S8800/S8800 LSP Solution at Main Site = 99.9993% *Failover is connection preserving, so stable calls survive Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data (> 2,200+ system years per quarter) with S8730, S8510 and S8300 servers. S8800 performance is expected to be equal or better. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 17
    • Midsize Enterprise Case Study Availability Assumptions (1 of 2)  Gateway failover to LSP is connection preserving (stable calls survive during failover) for all calls. The 3 minutes of down time (includes failure detection, failover, gateway reset by LSP, phone re-registration) is only experienced by small percentage of users and depends on the call rate.  Avaya Aura Communication Manager supported on S8800 equipped with RAID 1 Disk mirroring and optional redundant power supplies, has availability prediction of 99.996%.  2,400 IP phone re-registration to PE supported on S8800 ~ 1 minute.  IP-phones TCP keep alive interval default value is 5 seconds with administrable count. The default is 5. Phones will discover that they have lost the signaling channel within 25 to 45 seconds of the actual outage.  H.248 gateway sends keep alive signals to Communication Manager every 15 seconds with failure threshold of 3 times. Communication Manager sends keep alive to the gateway every 20 seconds.  Number of alternate gatekeepers for the IP-phones is up to 16 gate keepers and up to 4 for H.248 gateways. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 18
    • Midsize Enterprise Case Study Availability Assumptions (2 of 2)  Cluster of H.248 gateways provide N+1 DSP resources and N+1 T1/E1 resources providing service in active/active mode (parallel).*  Single G450 Gateway with the option of redundant power supply (hot swap FRU) has availability value > 99.995%.  Gateway reset by new active server < 1 minute.  TTS phones and Short Network Outage: TTS enabled IP-phone does not lose registration to the primary server and is back in service immediately after the network heals.  Standard Local Survivable (SLS) feature on H.248 gateways: with this feature the gateway itself contains basic call control ability if connection to the main server is lost.  PSTN fall back capabilities in the event of WAN outages. *Note: Gateways must be in connecting network regions For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 19
    • Achieving Better than Five Nines Availability with Avaya Aura™ Large Enterprise Solutions (> 2,400 endpoints) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 20
    • Single Site Large Enterprise Solution on S8800 Server Pair with PE Duplication (> 2,400 endpoints, H.248 Gateways) With Better than Five Nines Availability Main Site > 5-9s availability  Avaya Aura Communication Manager on S8800 Server Pair with Processor S8800 server with Processor Ethernet Ethernet Duplication (PE) duplication  End to end signaling and media processor redundancy – for IP phones and H.248 gateways  Call Preserving server interchange Redundant Customer LAN  IP phone registrations preserved through server interchange  Gateway registrations preserved through server interchange  Port Network calls survive through short network outages  Cluster of gateways providing N+1 DSP resources and ISDN T1/E1 trunks PSTN Source: Avaya Labs For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 21
    • Multi Site Large Enterprise Solution on S8800 Server Pair with PE Duplication (> 2,400 endpoints, H.248 Gateways) Main Site > 5-9s availability Remote Site ≥ 4-9s availability  Communication Manager with SLS, S8300 LSP or S8800 LSP  Simplex WAN link to branch is subject to failure  Local stable calls survive during failover, calls over WAN will fail  When failover is complete, calls over WAN will fall back over PSTN For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 22
    • Multi Site Large Enterprise Solution on S8800 Server Pair with PE Duplication (> 2,400 endpoints, H.248 Gateways) With Better than Five Nines Availability Main Site > 5-9s availability Remote Site = 5-9s availability  Redundant WAN link improves site availability  LSP in branch + cluster of gateways  Local stable calls survive during failover  Calls over WAN will fail (but redundant WAN reduces failures) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 23
    • Large Enterprise Case Study Availability Calculation for S8800 Server Pair with Processor Ethernet Duplication and H.248 Gateways - Main Site S8800 Server Pair with Processor Ethernet Duplication > 99.9999% Cluster of H.248 gateways providing N+1 DSP resources and ISDN T1/E1 trunks > 99.9999% Redundant Customer LAN 99.9999% Server failover occurs in < 45 seconds and there is no service interruption = 0 0 minutes minutes of downtime Availability from input of above data in Markov failure transition model = 99.9999% Power/Environmental availability x 99.99955% Availability for Main Site > 99.9994%* *Due to complexity and scale of Large Enterprise Solutions availability calculations may vary Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data (> 2,200+ system years per quarter) with S8730, S8510 and S8300 servers. S8800 performance is expected to be equal or better. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 24
    • Large Enterprise Case Study Availability Assumptions for S8800 Server Pair with Processor Ethernet Duplication & H.248 Gateways  S8800 server pair has memory shadowing capability. This solution is call preserving during server interchange (no interruption in service).  TTS enabled IP-phones registration is retained during interchange.  H.248 gateway registration retained during interchange.  Fully redundant signaling paths for phones and gateways via Processor Ethernet .  Pool of N+1 DSP resources and trunk groups available on cluster of G450 Gateways.  G450 failover to LSP < 3 minutes.  6,000 IP phone re-registration to Processor Ethernet (PE) < 2 minutes. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 25
    • Single Site Large Enterprise Solution on S8800 with Mixed IP Connect & Processor Ethernet (> 2,400 endpoints, G650/H.248 Gateways) With Better than Five Nines Availability Main Site > 5-9s availability  Avaya Aura Communication Manager on S8800 server pair with mixed Processor Ethernet (PE) duplication  End-to-end signaling and media processor redundancy  G650 can provide redundant IPSI, power supply, media processing board and N+1 CLAN and trunks  Clustering of H.248 gateways N+1 DSP resources and ISDN T1/E1 trunks  Call Preserving server interchange  Gateway and IP phone registrations preserved through server interchange  Port Network calls survive through short network outages Source: Avaya Labs For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 26
    • Multi Site Large Enterprise Solution on S8800 with Mixed IP Connect & Processor Ethernet (> 2,400 endpoints, G650/H.248 Gateways) Main Site > 5-9s availability Remote Site ≥ 4-9s availability  Communication Manager with SLS, S8300 LSP or S8800 LSP  Simplex WAN link to branch is subject to failure  Local stable calls survive during failover, calls over WAN will fail  When failover is complete, calls over WAN will fall back over PSTN For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 27
    • Multi Site Large Enterprise Solution on S8800 with Mixed IP Connect & Processor Ethernet (> 2,400 endpoints, G650/H.248 Gateways) With Better than Five Nines Availability Main Site > 5-9s availability Remote Site = 5-9s availability  Redundant WAN link improves site availability  LSP in branch + cluster of gateways  Local stable calls survive during failover  Calls over WAN will fail (but redundant WAN reduces failures) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 28
    • Large Enterprise Case Study Availability Calculation for S8800 Server Pair with Mixed IP Connect and Processor Ethernet (G650/H.248) - Main Site S8800 Server Pair with mixed IP Connect and Processor Ethernet > 99.9999% Single G650 Gateway > 99.9995% Cluster of H.248 gateways > 99.9999% Redundant Customer LAN 99.9999% Server failover occurs in < 45 seconds and there is no service interruption = 0 0 minutes minutes of downtime Availability from input of above data in Markov failure transition model > 99.9998% Power/Environmental availability x 99.99955% Availability for Main Site > 99.999%* *Due to complexity and scale of Large Enterprise Solutions availability calculations may vary Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data (> 2,200+ system years per quarter) with S8730, S8510 and S8300 servers. S8800 performance is expected to be equal or better. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 29
    • Large Enterprise Case Study Availability Assumptions for S8800 Server Pair with Mixed IP Connect and Processor Ethernet (G650 / H.248 Gateways)  S8800 server pair has memory shadowing capability. This solution is call preserving during server interchange (no interruption in service).  TTS enabled IP-phones registration is retained during interchange.  H.248 gateway registration retained during interchange.  Fully redundant signaling paths via Processor Ethernet and IPSI boards.  Fully redundant media path (320 Media Processor Board on G650).  N+1 Trunk cards on G650.  Pool of N+1 DSP resources and trunk groups available on cluster of G450 Gateways.  S8800 ESS capacity is the same as the S8800 primary server pair.  Stable calls on G650 will survive control network outages of up to 2 minutes.  G650 and G450 Gateway failover to ESS in under 5 minutes.  6,000 IP phones re-registration to Processor Ethernet (PE) < 2 minutes. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 30
    • Acronyms  CLAN: Control LAN interface  MTBF: Mean Time Between Failure  DSP: Digital Signal Processor  MTTR: Mean Time to Repair  ESS: Enterprise Survivable Server  PE: Processor Ethernet  HW: Hardware  PN: Port Network  ISDN: Integrated Services Digital  PS: Power Supply Network  SLS: Standard Local Survivable  IGAR: Inter Gateway Alternate Routing  SSD: Solid State Drive  IPSI: IP System Interface  SW: Software  LAN: Local Area Network  TTS: Time to Service  LSP: Local Survivable Processor  UPS: Uninterruptible Power Supply  MG: Media Gateway / Gateway  WAN: Wide Area Network For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 31
    • Achieving Five Nines Availability with Avaya Aura™ Methodology and Assumptions For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 32
    • Notes on Availability Calculations (1 of 4) Why Markov Failure Transition Model  Failure modes play a significant role in system reliability modeling and requirements. System reliability modeling involves identifying a system’s failure modes. Mathematical models are then developed to predict the amount of time spent in those failure modes and the rate at which the system fails.  Markov Chain Reliability Modeling is used as the mathematical model for predicting total system availability. The advantage of this technique over others (for example, the parts count and combinatorial models) is its ability in capturing the fault-tolerant aspect of the platform. Avaya Aura products are designed to continue service in the face of many failure events. Stable calls stay up in the event of loss of connectivity to the primary server. IP-phones, Port Networks and gateways do not lose registration in the event of short network outages. Such resiliency is captured in the mathematical model in assessing total system availability. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 33
    • Notes on Availability Calculations (2 of 4) Branch Availability and its Dependence on Network Availability  Customer Network Availability: high system availability makes the assumption that customer network is designed with Best Practice Networking. – Ref: http://support.avaya.com/elmodocs2/comm_mgr/r5.0/245600_6.pdf  When the network connection is redundant, failure in one link is detected in few seconds and traffic is re-routed in less than one minute of the failure. On the rare occasions when the outage is not detected or lasts longer than 45 seconds remote gateways and phones will search for an alternate gatekeeper and thus will be in service long before the link failure heals.  The frequency of such events is small and since failover to LSP is connection preserving, a very small number of users (~ 5%) experience the service outage and total downtime they experience per failure is no longer than 1-2 minutes.  In a configuration that has a single WAN connection to the remote branch site, the frequency of link failures will lead to higher number of failover to LSP or ESS. Such events can occur as many as 2-3 events per month and each can last minutes or hours. Avaya gateways and phones will detect loss of service from the primary server and will search for service from the LSP within 45 seconds of the link loss.  When the failover is complete (under 3 minutes), WAN calls will fall back to PSTN. Since failover is connection preserving, only a small number of calls (5% in 3 minutes) will be impacted. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 34
    • Notes on Availability Calculations (3 of 4) Example 1:  When the connection over the WAN is redundant: – WAN Link connection Availability = 99.999% – Expect 2-3 outage events per year which last longer than 45 seconds. WAN MTBF = 4 to 6 months – LSP failover is complete in less than 3 minutes (failure detection, MG reset, IP phone registration.) Branch MTTR = 3 minutes – Outage in Branch is experienced by < 5% of the traffic* What do we experience in Branch?  Downtime/year 2-3 outages x 3 minutes x 5% =18 to 27 seconds Average downtime experienced per end user as the result of WAN failure events (1- (27 seconds)/(seconds in a year))=99.99991%  Include server/LSP and power/environment availability  Branch Availability over redundant WAN link: 99.9998% x 99.99955% x 99.99991% = 99.9993% *Note that in fact in our testing labs the detection and failover completes in less than 2 minutes. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 35
    • Notes on Availability Calculations (4 of 4) Example 2:  When the connection over WAN is non-redundant: – WAN link connection availability = 99% to 99.5% – This type of connection experiences 2-4 outages per month and each can last hours WAN MTBF = 1- 2 weeks, WAN MTTR = 0.5 – 4 hours – LSP failover is complete in less than 3 minutes (failure detection, MG reset, IP phone registration) – In less than 3 minutes WAN calls will fall back to PSTN and it is business as usual. Branch MTTR = 3 minutes – Outage in Branch is experienced by < 5% of the traffic What do we experience in Branch?  Downtime/year 24 – 52 outages x 3 minutes x 5% = 3.6 – 7.8 minutes Average downtime/year experienced per user due to WAN failures (1-(8 minutes)/(minutes in a year)) = 99.998%  Include server/LSP and power/environment availability  Branch Availability over non-redundant WAN link: 99.995% x 99.99955% x 99.998% = 99.992% For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 36
    • Branch Availability Calculation (1 of 8) G450 Gateway with Standard Local Survivable (SLS) and Simplex WAN link to Remote Site Communication Manager on primary server at Main Site 99.995% H.248 gateway with Standard Local Survivable (SLS) at Branch 99.995% Redundant Customer LAN 99.9999% Simplex WAN/Internet 99.5% Time to complete failover < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.995% Power/Environmental availability x 99.99955% Availability for Remote Site > 99.99% Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data ( 2,200+ system years per quarter) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 37
    • Branch Availability Calculation (2 of 8) S8300 LSP with Simplex WAN link to Remote Site S8300 primary server supported in H.248 gateway at Main Site 99.995% S8300 Local Survivable Processor (LSP) supported in H.248 gateway at Branch 99.995% Redundant Customer LAN 99.9999% Simplex WAN/Internet 99.5% Time to complete failover < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.995% Power/Environmental availability x 99.99955% Availability for Remote Site > 99.99% Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data ( 2,200+ system years per quarter) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 38
    • Branch Availability Calculation (3 of 8) S8300/S8300 LSP with Redundant WAN link to Remote Site S8300 primary server supported in H.248 gateway at Main Site 99.995% S8300 as LSP supported in H.248 gateway at Branch 99.995% Redundant Customer LAN 99.9999% Redundant WAN/Internet 99.999% Time to complete failover < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.9997% Power/Environmental availability x 99.99955% Availability for Remote Site = 99.9993% Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data ( 2,200+ system years per quarter) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 39
    • Branch Availability Calculation (4 of 8) S8800 LSP with Simplex WAN link to Remote Site S8800 primary server at Main Site 99.996% S8800 Local Survivable Processor (LSP) at Branch 99.996% Redundant Customer LAN 99.9999% Simplex WAN/Internet 99.5% Time to complete failover < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.995% Power/Environmental availability x 99.99955% Availability for Remote Site > 99.99% Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data ( 2,200+ system years per quarter) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 40
    • Branch Availability Calculation (5 of 8) S8800/S8800 LSP with Redundant WAN link to Remote Site S8800 primary server with redundant power at Main Site 99.996% S8800 as LSP with redundant power at Branch 99.996% Cluster of G450 Gateways at Branch > 99.9999% Redundant Customer LAN 99.9999% Redundant WAN/Internet 99.999% Time to complete failover < 3 minutes x 5% of Busy Hour traffic affected = 0.15 0.15 minutes minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.998% Power/Environmental availability x 99.99955% Availability for Remote Site = 99.999% Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data ( 2,200+ system years per quarter) For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 41
    • Branch Availability Calculation (6 of 8) S8800 Server Pair/S8800 or S8300 LSP with Simplex WAN link to Remote Site S8800 primary server pair at Main Site > 99.9999% S8800 or S8300 as LSP with redundant power at Branch 99.996% Cluster of G450 Gateways at Branch > 99.9999% Redundant Customer LAN 99.9999% Simplex WAN/Internet 99. 5% H.248 gateway time to complete failover to LSP < 3 minutes x 5% of Busy Hour traffic 0.15 minutes affected = 0.15 minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.9995% Power/Environmental availability x 99.99955% Availability for Remote Site = 99.999% *Due to complexity and scale of Large Enterprise Solutions availability calculations may vary Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data (> 2,200+ system years per quarter) with S8730, S8510 and S8300 servers. S8800 performance is expected to be equal or better. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 42
    • Branch Availability Calculation (7 of 8) S8800 Server Pair/S8800 LSP with Redundant WAN link to Remote Site S8800 primary server pair at Main Site > 99.9999% S8800 LSP with redundant power at Branch 99.996% Cluster of G450 Gateways at Branch > 99.9999% Redundant Customer LAN 99.9999% Redundant WAN/Internet 99.999% H.248 gateway time to complete failover to LSP < 3 minutes x 5% of Busy Hour traffic 0.15 minutes affected = 0.15 minutes average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.9995% Power/Environmental availability x 99.99955% Availability for Remote Site = 99.999% *Due to complexity and scale of Large Enterprise Solutions availability calculations may vary Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data (> 2,200+ system years per quarter) with S8730, S8510 and S8300 servers. S8800 performance is expected to be equal or better. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 43
    • Branch Availability Calculation (8 of 8) S8800 Server Pair/S8800 LSP with Redundant WAN link to Remote Site S8800 primary server pair at Main Site > 99.9999% S8800 ESS with redundant power at Branch 99.996% G450 Gateways and G650 Gateway at Branch > 99.9999% Redundant Customer LAN 99.9999% Redundant WAN/Internet 99.999% Time to complete failover to ESS < 5 minutes x 20 % of Busy Hour traffic affected = 1 1.0 minutes minute average experienced downtime per failure Availability from input of above data in Markov failure transition model = 99.9994% Power/Environmental availability x 99.99955% Availability for Remote Site = 99.999% *Due to complexity and scale of Large Enterprise Solutions availability calculations may vary Note: Avaya Aura Communication Manager software reliability and availability data is based on analysis of thousands of hours of field data (> 2,200+ system years per quarter) with S8730, S8510 and S8300 servers. S8800 performance is expected to be equal or better. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 44
    • LAN/WAN Design for High Availability  Because of the resource scarcity (high costs and lower bandwidths) in a WAN environment, problems are more likely to manifest themselves in running IP Telephony over a WAN versus on a LAN. Thus achieving better than 5 nines is more challenging in the WAN environment than in the LAN. What is a Reliable Customer LAN/WAN:  Highly Reliable Networks can be achieved through the application of three fundamental principles: Simplicity, Manageability and Scalability – Simplicity: IT staff must interact with the network, so if the system is difficult to understand the probability of error increases. – Manageability: management capabilities and tools are required for implementation of reliable change control procedures, to prevent improper network configurations and to aid in detecting and reporting errors. – Scalability: using designs that limit the impact of changes reduces the potential for error. Excess bandwidth, unused ports and available addresses are required to verify changes and to simplify network expansion. Modularity, design reuse, and testability are all attributes of highly reliable networks. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 45
    • Redundant (or Multipath) LAN/WAN (1 of 2)  For the purpose of meeting high availability, the most commonly recommended network topology consists of a redundant core with building blocks of layered routers and switches.  Multiple paths or link redundancy will minimize the disruption of service due to hardware failure events, link congestions, denial of service attacks, etc. When a failure in one link is detected, traffic will switch over to the healthy link. Link redundancy accommodates the move of an endpoint or gateway from one switch to the other.  It is important that the bandwidth of all links be equivalent and adequate to handle the aggregated traffic.  In Layer 2, Protocols such as Spanning Tree will allow loop free topology and Link Aggregation Group (LAG) protocols will allow for quick discovery of failure and removal of the failed link. This will reduce the convergence time to be nearly instantaneous.  In Layer 3 switching, Routing Protocols will allow routers to dynamically learn the topology of the network. Should the topology of the network change, routing protocols update their internal topology table, which allows them to route around the failure. – Protocols such as Virtual Router Redundancy (VRRP) provide a mechanism to deal with router failure without disrupting endpoints or gateways. For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 46
    • Redundant (or Multipath) LAN / WAN (2 of 2)  Example of a redundant topology: OSPF manages redundancy toward the network core Layer 3 (Distribution) Virtual Router Redundancy Protocol manages Layer 3 redundancy toward the cluster Layer 2 Rapid Spanning Tree is used to manage Layer 2 (Access) redundancy Note: Direct switch to switch Layer 2 connection required if Layer 3 devices do not provide Layer 2 switching For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 47
    • Reliable Software Design Principles (1 of 4)  Software failures are due to design flaws and logical errors made during development. – Avaya Aura Communication Manager software architecture is designed with modular functionality and a fault resistant architecture – Modules address specific sub-functions with cohesion and low coupling – Built on Linux, which has fewer security flaws than other operating systems and facilitates system customization to provide further security  Software systems built from existing components typically have better reliability and lower defect rates than systems built from scratch – Years of applied dedication in software design have made Communication Manager software a rock solid block – Pervading all aspects of design is a continual architectural diligence toward a consistent, logical system structure that allows an easy evolution to the future – Each release appropriately reuses proven foundations from the past For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 48
    • Reliable Software Design Principles (2 of 4)  System must be capable of monitoring itself to detect fault conditions, when a failure occurs, the design itself must help alleviate the impact of the failure  Communication Manager (CM) maintenance architecture delivers built-in intelligence and self healing abilities for systems at all levels – CM software plays a central role in achieving high availability as more than 30 percent of the lines of code are devoted to the maintenance subsystem – CM software is designed to automatically and continually assess performance, detecting and correcting errors as they occur – Software incorporates component & sub-assembly self-tests, error detection/correction, system-recovery, and alarm escalation paths – The maintenance subsystem manages hardware operation, software processes and data relationships For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 49
    • Reliable Software Design Principles (3 of 4)  Reducing Mean Time to Restore Service (MTTR) depends on event reporting, logging, and when possible automated remote maintenance – The High Availability Platform (HAP) part of Communication Manager software incorporates watchdog type monitoring of: • health and sanity of the applications • base operating system • critical environmental conditions – Degradation of service results in simultaneous recovery strategies as well as alarming to services if necessary – If such levels of software reboots fail, then the recovery escalates to server hard reset – All this is done without the need for dispatch to the site and hence reduces MTTR to no more than few minutes For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 50
    • Reliable Software Design Principles (4 of 4)  Software quality check and assessing software reliability – Avaya carefully examines every step of software development by measuring faults during coding phase – Software performance and reliability/recovery aspects are tested in system verification lab, product introduction and later in the field – Bugs and Modification Request Metrics are included as part of the data used in assessing software reliability prediction* – Avaya system availability analysis involves measuring software field performance data of over 12,000 systems in the field *Note: According to the methodology recommended by Telcordia GR-2813-CORE, Software Reliability Prediction For more information contact us at www.packetbase.com or 866.405.3992 - © 2010 Avaya Inc. All rights reserved. 51
    • thank you PacketBase, Inc. www.packetbase.com 866.405.3992