Remote test that QoS.A real-life circuit test can solve problems before the customer picks up the phone or switches on the modern.
Teleport Communications Group Teleport Communications Group (TCG) was the first Competitive local exchange carrier (CLEC) in the U.S. First formed in 1985, it competed with the existing telephone companies to provide dial tone and related services in the largest U.S. markets. , Inc. (TCG (Trusted Computing Group, Beaverton, OR, www.trustedcomputinggroup.org) The successor to the Trusted Computer Platform Alliance (TCPA), announced in 2003 by founding members AMD, HP, IBM, Intel and Microsoft. ) provides local telephone service in 65 major markets nationwide. When the company began implementing ISDN ISDN
in full Integrated Services Digital Network
Digital telecommunications network that operates over standard copper telephone wires or other media. services in 1997, it wanted a solution to remotely monitor and test ISDN circuits before connecting customers to the network. The company also wanted the capability of remotely duplicating customer applications to rapidly resolve problems.
To meet these objectives, TCG had to be able to test a circuit using real traffic before it went on line. Sergio Santiago, the company's ISDN product manager, says, "Other local carriers dispatch technicians first and troubleshoot after. TCG wanted a way to test the circuit with real digital signals and the ability to accurately simulate an individual customer's traffic. We needed to be able to do complete end-to-end testing from the network management center (NMC NMC Nursing & Midwifery Council (UK)
NMC NSSDC Master Catalog (NASA)
NMC Northwestern Michigan College (Traverse City, Michigan)
NMC National Meteorological Center ). We wanted to be sure that when we connected ISDN customers, they had a working line. Also, if they had problems, we wanted to rapidly isolate the cause and get them back on line quickly without the delay of dispatching service personnel to the site."
TCG selected the TSI-1567 ISDN Test Unit (ITU (International Telecommunication Union, Geneva, Switzerland, www.itu.ch) A telecommunications standards body that is under the auspices of the United Nations. Comprising more than 185 member countries, the ITU sets standards for global telecom networks. ), from Telesync, Inc., of Norcross, Ga., to handle the testing requirements. The ITU can place and receive calls and combines the features of a protocol analyzer See network analyzer. and multichannel Using two or more paths for transmission or processing. It can refer to a variety of architectures including (1) multiple I/O channels between the CPU and peripheral devices, (2) multiple wires in a cable, (3) multiple "logical" channels within a single wire or fiber or (4) multiple bit error rate test set (BERTS BERTS Bit Error Rate Test Set
BERTS Basic Exchange Radio Telecommunications Service ) in a single unit. It provides a dial-up means of automatically looping back or generating BERT (Bit Error Rate Test) An analysis of network transmission efficiency that computes the percentage of bits received in error from the total number sent. patterns on any of the 23 DS-0 B channels in an ISDN PRI ISDN PRI Integrated Services Digital Network Primary Rate Interface (also seen as ISDN-PRI) DS-1 stream. The TSI- 1567 ITU is used to troubleshoot BONDed calls, switched digital services, and translation tables in switches.
One ITU is located in every switch location. As new switches are brought on line, they are immediately outfitted with an ITU. In this way, the ITU can be used to turn up PRI PRI: see Institutional Revolutionary party.
(Primary Rate Interface) An ISDN service that provides 23 64 Kbps B (Bearer) channels and one 64 Kbps D (Data) channel (23B+D), which is equivalent to the 24 channels of a T1 line. service to the customer, as well as provide a maintenance and troubleshooting tool when required.
A dial-up modem is used to access the RS-232 port of the ITU. Local operations personnel, as well as the NMC personnel, can dial into any ITU in the network of switches to monitor or test any PRI application.
Accessing the ITU, the operation and maintenance personnel can emulate the end user's applications and determine in a matter of minutes A Matter of Minutes is an episode from the television series The New Twilight Zone. Cast
The network switch is translated to route the incoming calls assigned to the ITU into the DS- 1 applied to the unit. The switch translations that affect the ITU can be changed to mirror a customer's PRI application, giving the operations personnel the capability to exactly emulate the customer's application at the Layer 2 and 3 level, namely, call setup and network control.
Upon receiving a trouble call from a customer, the NMC personnel dial up the switch ITU in the city where the trouble is reported. The test format is built on the display screen of the workstation and a call is placed to the customer's application. Layer 1, 2, and 3 information is scanned using the ITU's overview, L1, L2, and L3 screens. The log screen will show the messages transmitted and received by the switch from the customer's application on the D channel.
This method of sectionalization--the determination of "trouble in or out" takes approximately 20 seconds, the length of time it takes to place a call. If the call is successful, the speed of the call (56K or 64K) is determined, as well as whether it is voice or data, and, most importantly Adv. 1. most importantly - above and beyond all other consideration; "above all, you must be independent"
above all, most especially , the destination of the call. By changing the translations of the ITU to match those of the customer, including trunk routing and long-distance carrier selection and routing index, the technician can place the same call as the customer into the network and to the far-end destination. In this instance, the overview and log formats will be most helpful in analyzing a failure, if one occurs.
To date, network call failures are typically of two types. One is calls made utilizing a long-distance carrier whose networks are not end-to-end 64K. The other is calls routed through tandem switching arrangements and meet-point trunking locations that do' not have sufficient trunking capacity to accept the ISDN traffic loads. A call can be placed into the network at 64K, but there is no guarantee that it will complete at 64K.
As more and more carriers upgrade their networks to 64K clear-channel capability, the problem of placing and receiving 64K calls should disappear.
TCG's monitoring/testing strategy was designed in cooperation with Odyssey Solutions, Inc. "TCG has taken a proactive approach to providing quality customer service by implementing a maintenance strategy before it introduced its primary rate ISDN service offerings," says Warren Schmitt, Odyssey's chief technology officer. "This will provide significant benefits for its ISDN customers."
Circle 269 for more information from Telesync, Inc.