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Network Evolution II. John Wright jcwright@bell.net. 1976 to …. Canadian Scene. NT. BCT. AGT. Telus. SGT. IT. MTS. NBT. SaskTel. MT&T. QT. Bell. BC Tel. Alberta Government Tel. Saskatchewan Govt. Tel. Manitoba Telephone System Bell Canada. Quebec Tel. NB Tel.
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Network Evolution II • John Wright • jcwright@bell.net 1976 to …. Network Evolution II
Canadian Scene NT BCT AGT Telus SGT IT MTS NBT SaskTel MT&T QT Bell BC Tel. Alberta Government Tel. Saskatchewan Govt. Tel. Manitoba Telephone System Bell Canada Quebec Tel. NB Tel. Maritime Tel. & Tel. Island Tel. Newoundland Tel. Network Evolution II
Add Cellular Telus NT R O G E R S IT MTS NBT Bell MT&T QT SaskTel Network Evolution II
Network Improvements • Transmission • FOTS • Switching • Electronic, digital • Signalling • Common Channel (Data Network) • Dynamic Routing Network Evolution II
Transmission • Fibre • Most heavy route LD • Redundancy designed in • To the home • Heavy route microwave – gone • Short and/or light route microwave – almost gone • Microwave or cable (paired or co-ax) being replaced by FOTS Network Evolution II
Switching • Electromechanical • Gone • Electronic - Analogue • Look hard, you may find some • Electronic – Digital • Almost universal • Electronic – Optical • Coming ?? Network Evolution II
Montreal Switching Hierarchy 613 416, 519705 514 819 Class 1 Regional Centre Class 2 Sectional Centre Trunks Class 3 Primary Centre Class 4 Toll Centre Class 5 End Office Loops Network Evolution II
Numbering Plan Country Code 1, 2 or 3 digits (Canada & US is 1, UK is 44, Taiwan is 886) Area Code 3 digits, middle is 0 or 1 (Eastern Ontario is 613) C. O. Code 3 digits, first one is not 0 or 1 (Carleton is 520) Subscriber 4 digits (Halim Yanikomeroglu is 5734) 1 - 613 - 520 - 5734 is unique Problem – North America ran out of area codes Solution – remove the 0 or 1 restriction Network Evolution II
Signalling • Common Channel Signalling • A data network • Computer access • Separation between voice and signalling • Signalling information for many voice channels on one signal channel • Effectively a data network • Before, after and during Network Evolution II
CCS Format • Based on the OSI model B I B F I B F CK SIF SIO LI FSN BSN F 8 16 8 2 6 1 7 1 7 8 8n ( n= 2 to 256) F Flag BSN Backward Sequence Number BIB Backward Indicator Bit FSN Forward Sequence Number FIB Forward Indicator Bit LI Length Indicator SIO Service Information Octet SIF Signalling Information Field CK Check Bits Network Evolution II
OSI & CCS7 CCS 7 OSI Model 7 Application 7 Application TUP MAP 6 Presentation 6 Presentation 5 Session 5 Session 4 Transport 4 Transport 3 Network 3 Network 2 Data Link 2 Data Link 1 Physical 1 Physical TUP - Telephone User Part MAP – Mobile Application Part Network Evolution II
CCS Basic Architecture Sw. A Sw. B Signal Transfer Point (STP) Trunks Sw. C Disassociated Associated Network Evolution II
CCS7 Network Architecture TOLL (Primary ) STPs STP STP STP STP Links to Secondary STPs STP STP Network Evolution II
Mobile Application Part • Provides Services to Mobile Phone Users • Location management • Call handling • Routing • Roaming • Called party availability • Etc. • Originally used RADIUS • Remote Authentication Dial In User Service • Now ‘Diameter’ • Internet Engineering Task Force Network Evolution II
HPR COMPUTER HPR - Dynamic Routing VANC (or CAL, EDM, etc) St. JOHNS (or HFX, etc.) OT Trunks Control Monitoring TORONTO MONTREAL Effective in big-city networks Network Evolution II
The Balance Shifts • Long distance • Cost and price plummet • No longer the financial mainstay • Built-in to cellphone service • Local service • New services with good revenues • BUT Competition from cellphones Network Evolution II
CLASS Services • Call Forwarding • Calling Line ID • Calling Line ID Blocking • Auto Recall • Auto Call Back • Call Waiting • Ident-a-call Network Evolution II
Intelligent Services 1 Switch 800 (888, 877, 866) Signalling links Database The 800 database can be programmed to return different numbers depending on the calling number, calling location and time-of-day Network Evolution II
Intelligent Services 2 Switch Calling Card Checking Signalling links Database The Calling Card database fully automates the Q & A between an ‘operator’ and the customer Network Evolution II
Bell LD Bell local Interconnection Issues Bell local Other local Bell LD Other LD Bell LD Other LD Bell local Other local Bell local • How do you connect? • How do you share the revenue? Network Evolution II
Internet - Origins • 1969 ARPAnet • 1980s NSFnet (US), CA*net (Canada) • 1991 HTML (CERN) WWW • 1993 Mosaic Netscape Public Business Academia Network Evolution II
Summary The key words are Change & Competition • 100 years of control, growth and industrial stability • Followed by 20 years of change • Followed by tumult • Leading to: - Anarchy? - Chaos? - Survival of the fittest • The technology is digital Network Evolution II
Is the Network Relevant? • Yes • All voice traffic is carried on the network • Including LD cellphone calls • All Internet traffic is carried on the network • All other data is carried on the network • But • It is becoming a passive carrier • Services are provided at the ends Network Evolution II