Voice Gateway

Use access servers filled with digital modems (currently (formerly?) used for analog modem pools) as voice gateways or special purpose gateways such as that of Li Wei [Li Wei 1994]. (Li Wei created the first E1 to Ethernet gateway that looked like part of a Ericsson PBX - hence all of the services of this distributed PBX were available.)

Many Analog Telephony Adapters (ATAs) exist: Cisco ATA 186, Linksys SPA2102, Linksys SPA3000 or SPA3102 (FXS + FXO port for gatewaying to/from PSTN), … .

The box on the lower left is a modem chip

Slide Notes

Li Wei, “Gateway between Packet and Switched Networks for Speech Communication”, M.Sc. Thesis, KTH/Teleinformatics, September 1994.

Transcript

[slide36] As I mentioned, voice gateways done with ISDN lines or analog telephony interfaces, really, really very simple.