There is one handout today at the front and back of the room! ppt

4ess Switch. Copyright © 2003, Lucent Technologies. All Rights Reserved.August 11, A It was introduced in Chicago in January 1976, to replace the 4A crossbar switch On January 17, 1976, the first 4ESS™ switch was placed into service, culminating the single largest switch development ever undertaken in the Bell System until that time

Figure 1 from The evolution of the 4ESS™ switch Semantic Scholar
Figure 1 from The evolution of the 4ESS™ switch Semantic Scholar from www.semanticscholar.org

This switch, the #4ESS, was the replacement for the large numbers of #4A Crossbar tandem switches that were in use at the time. Page 1 Task Oriented Practice (TOP) 4ESS Switch Common Network Interface START Do you understand Go to 893 Go to 001 how to use TOP TOP Comments Hot Line: Issue 8 OCT 1996 Monday through Friday 8:00 a.m

Figure 1 from The evolution of the 4ESS™ switch Semantic Scholar

The VERY FIRST #4ESS toll switch, CHCGILCL57T, Chicago 7 IL (initially classed/ranked as a High Volume SRT- Selective Routing Tandem, 312-10; later reclassed as a Cl.2/SRT, 312-2) was installed in Jan 1976, BEFORE the last #4A-ETS XB toll switch, MDSNWI0241T, 608-2, Madison 2 WI was installed in May 1976 4 ESS Switch Translations Guide TG4 (7 Vols.) 234-010-100AC 3/00 Proprietary Translations Guide 4 ESS Switch PTG4 234-010-108 2 4ESS-2000Switch Maintenance Procedures 234-010-120 2 Digital Synchronization — Refer-ence Guide (5-92) 234-010-131 9.2 4ESS/APS Input Reference Manual 234-010-132 1.6 4ESS Switch Input Reference When it was introduced, the 4ESS switch was the largest high-capacity digital switch in existence, capable of terminating 107,520 trunks and completing over 500,000 calls per hour

There is one handout today at the front and back of the room! ppt. [1] The last of the 145 systems in the AT&T network was installed in 1999 in Atlanta. This switch, the #4ESS, was the replacement for the large numbers of #4A Crossbar tandem switches that were in use at the time.

Figure 2 from The evolution of the 4ESS™ switch Semantic Scholar. 4 Electronic Switching System (4ESS) is a class 4 telephone electronic switching system that was the first digital electronic toll switch introduced by Western Electric for long-distance switching This time it was not an local central office switch, but a long-haul tandem switch