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PSTN Migration Methodology. The following slides provide detail of: PSTN Disconnection transfer activity Selected method Methods considered Impact on end customer service. Simon Rogers 21CN MSAN Transfer Engineering
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PSTN Migration Methodology • The following slides provide detail of: • PSTN Disconnection transfer activity • Selected method • Methods considered • Impact on end customer service • Simon Rogers • 21CN MSAN Transfer Engineering • Enquiries about this presentation to Anthony.Stephens @BT.COM 21CN Customer Engagement
PSTN End Customer Migration.- These are the areas we have covered to date / plan to cover • End customer migration • Confirmation of Line disconnection methods • Data migration PSTN Line disconnection Impact on end customer service PSTN Fallback Line disconnection & data migration Compression & Grooming I&MWG Nov - Dec 2005 I&MWG February 2006 I&MWG March 21st 2006 Planned I&MWG April 2006
BT Approach To End Customer Migration TE Workflow Management Decision not to fallback Go/No Go Decision Point - 36 - 12 Weeks - 12 Weeks + 7 Days Prepare Network Configure + Verify On the night Migration Monitor TE completion and handover 6pm CSS Data freeze 10pm Network Service frozen Activate data Connect to 21CN & Disconnect PSTN Modify PSTN call routing Update BT OSS Post transfer Tests Fault Handling 9am Freeze removed Monitor customer experience Monitor Network - resolve issues Initiate fallback if necessary Frames Uplift Customer data Audit Groom Legacy services to retained platform Compression Parallel connect 21CN to customer lines Capture and translate data Load data - start churn process Pre-transfer customer checks & audit Hand over to In-Life management
PSTN End Customer Migration Methodology • End customer migration comprises the following steps • 1) 21CN parallel connection - the end customers line is connected to 21CN and existing concentrator • 2) Data migration – end customer data is transferred from existing digital local exchange (DLE) to 21CN call server and MSAN • 3) PSTN disconnection & 21CN connection - the end customers line is moved from existing concentrator to 21CN enabling outgoing call capability • 4) PSTN call routing is transferred from existing digital local exchange (DLE) to 21CN call server enabling incoming calls
Test Head POTS E-side MDF Transfer in progress MDF E D PSTN DLE OVP PSTN CONC Customer lines OVP OVP 21CN TAM MSAN 21CN Voice 21CN T/TH • Transfer Activities • Command & Control confirm transfer “Go/No Go” • Disconnect PSTN concentrator & Switch 21CN TAM • Sync with changeover from DLE to Call Server
PSTN Disconnect MethodEvaluation Criteria • BT can have a single process that • Minimises risk of mistakes • Is suitable for both System X & AXE10 • Minimises impact on end customer service capability • Fast PSTN disconnection method • Fast Fallback re-connection (if required) • Lower risk disconnection & re-connection
PSTN Disconnection Methods Considered • A number of methodswere considered to complete the migration of end customer to BT’s 21CN platform that are suitable for both system X and AXE10, these include: • Removing Concentrator Plugs • Line Card Removal • Power Off Line Shelf Groups • Make Service Temporary Out Of Service (TOS) • Test Network Disconnection • Transfer Connectivity Point Disconnect
Method • Conc. • Type • Disconnection • (Seconds) • Fallback • (Seconds) • Remove Conc. Plug • (Slides 8 & 9) • System X • AXE10 • 126 – 515 • 500 – 750 • 315 • 750 • Line Card Removal • (Slides 10 & 11) • System X • AXE10 • 1000 • 1000 • 1000 (+ Power reset) • 1000 • Power Off Shelf Group • (Slide 12) • System X • AXE10 • 64 • 94 • 64 (+30 service delay) • 3280 • Make TOS • (Slide 13) • System X • AXE10 • 2000 • 547 • 2000 • 1000 • Test Network Disconnection • (Slide 14) • System X • AXE10 • N/A • N/A • N/A • N/A • Transfer Connectivity Point Disconnect • (Slide 15) • N/A • 400 • (200 strung) • 2400 PSTN Disconnection Evaluation Results
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 Selected PSTN Disconnect Method Concentrator Plug Removal System X shelf example MDF REAR SHELF VIEW 64 pair 32 pair connector plugs Slot Position Module C Module B Module A • 2 – 5 seconds per plug removal (Variants) • 5 seconds per plug replacement
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 Selected PSTN Disconnect Method Concentrator Plug Removal AXE10 shelf example MDF FRONT SHELF VIEW Slot Position BISS TSC L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C P O U P O U CLS CNAD SLCT EPMC REU ETB ETB 8 pair connector per line card 128 pair cable (3 x32 pair cables) 128 pair cable broken down to 8 pairs per connector. • 2 – 3 seconds per plug removal • 2 – 3 seconds per plug replacement
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Non Preferred Line Card Removal System X shelf example FRONT SHELF VIEW Slot Position L I N E C N T R L I N E C N T R L I N E C N T R P SU SLU (8) SLU (8) SLU (8) SLU (8) SLU (8) SLU (8) SLU (8) SLU (8) P SU D SLU (8) D SLU (8) D SLU (8) D SLU (8) P SU D SLU (4) D SLU (4) D SLU (4) D SLU (4) S P A R E S P A R E S P A R E S P A R E S P A R E Module A (Analogue 64 line) Module B (Digital 32 line) Module C (Digital 16 line) • 4 seconds per line card removal • 4 seconds per line card replacement (+ Power reset for some variants)
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 Non Preferred Line Card Removal AXE10 shelf example MDF FRONT SHELF VIEW Slot Position BISS TSC L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C L I C P O U P O U CLS CNAD SLCT EPMC REU ETB ETB 8 pair connector per line card 128 pair cable (3 x32 pair cables) 128 pair cable broken down to 8 pairs per connector. • 4 seconds per line card removal • 4 seconds per line card replacement
Non Preferred Power Off Line Shelf Groups • Removal of power to the concentrator line shelf / line controller module • System X • Suitable for providing required PSTN disconnect (2 seconds). However, some variants encountered 30 second delay to service provision on resumption of power. Additionally, faults sometimes raised on resumption of power. • AXE10 • Suitable for providing required PSTN disconnect (6 seconds). However, resumption of power requires maintenance action before service can be restored (2 – 3 minutes) Note: There is a risk that power supply units will fail when switched on again = Fallback impact
Non Preferred Make Service Temporary Out Of Service (TOS) • Use blocking command to block the service from the customer on the PSTN line • System X • Suitable for some variants but failed to provide required PSTN disconnect for some line card variants • AXE10 • Suitable disconnect for AXE10
Non Preferred Test Network Disconnection • Use ‘test network’ commands to block the service from the customer on the PSTN line • System X • Test network failed to provide required PSTN disconnection • AXE10 • Test network failed to provide required PSTN disconnection
Non Preferred Transfer Connectivity Point Disconnect • MDF TCP Module Only 21CN transfer connection point Cassette module TE disconnect TE disconnect point • 1 second per disconnect plug removal • 2 – 3 seconds per disconnect plug replacement
End User Experience • Outgoing calls • Short break in dial tone at point of 21CN cutover • No service interruption announcement during migration • Incoming Calls • Precise detail of service capability will become known upon completion of transfer engineering end to end trials phase. • Incoming call capability will be dependant upon size of number range and customer position within it. • A range of options are being considered as part of the transfer engineering solution to improve these timings. • Principle is to achieve the shortest service capability interruption possible