IP Backbones
Increasingly, the digital infrastructure of the PSTN is migrating from the TDM-based circuit-switched architecture to IP-based packet switching (see IP telephony). See digital loop carrier and AIN.
Switched, But Not Too Public
In 1886, this 50-line magneto switchboard, made by Bell Telephone of Canada, was used to switch voice calls in small localities. These instruments were the beginning of the worldwide PSTN. (Image courtesy of Nortel Networks.)
![]() | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2009 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- PC-Telephone 6.1 (Windows)
- Make FREE pc-to-pc, pc-pc and cheap pc-to-phone, pc-phone, pc-to-fax, pc-fax, phone-to-pc, phone-pc, fax-to-pc, fax-pc, sip-phone, sip-to-phone calls over Internet/VoIP or ISDN/PSTN telephone networks. Use your computer as internet telephone, USB phone, USB handset, ISDN telephone, ISDN fax, answer phone, fax software, voicemail, caller ID, CLIP/CLIR, audio conferencing, call answer, call...
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- Discussion threads 2009-10-15
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- Blog posts 2009-09-15
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- Software downloads 2009-07-31
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- Hunting for cool phones
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- Software downloads 2009-05-06
- What's going on with Skype for Business?
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- Discussion threads 2009-03-03
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- Blog posts 2009-03-02
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- White papers 2009-02-17
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- Training 2009-02-01
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- Blog posts 2008-12-15
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