Direct Inward Dial
Problem
You have a customer service oriented business. You sell goods
or services over the telephone. Perhaps you run a survey service.
Whatever your reason you've decided to add a WATS trunk to
your communications network in order to save money on outgoing
toll calls. You've contacted the LDC and they will provide
you with a WATS circuit from
their switch (Class 4) to your office.
Solution
Coastcom's 2-Wire FXO channel cards in LRB/DPT mode offer the
signaling states required to interface Direct Inward Dial (DID)
services on a LRB line.
How Does It Work?
With a DID circuit the CO is functioning the opposite of its
normal operation. The CO usually receives digits from the customer
(subscriber). With DID the CO is sending digits to the subscriber.
The FXO provides LRB signaling states back to the CO that comply
with DID operation. A DID circuit is incoming only.
|
Figure v1. Configuration for DID to PBX Connections
What Actually Occurs?
An outside caller dials the seven digit telephone number to your
business in order to speak to Marilee. The first three digits
for each individual is the same. For example Marilee's number
is 777-1234 and Ahmad's number is 777-1235.
When the CO receives the seven digit number it signals the FXO
to seize the line to the PBX. The PBX prepares to accept the
digits from the CO.
The PBX, when ready to accept digits, signals back with a LRB
wink (temporary battery reversal) to the CO. The CO passes the
four digit access number to the PBX. The PBX then rings Marilee's
extension.
When Marilee picks up (off-hook), the PBX applies LRB (held during
call) back to the CO. The CO starts answer supervision upon receiving
the LRB.
When Marilee finishes her call and hangs up, the PBX turns off
LRB and the CO discontinues billing.
The Direct Inward Dial features work on incoming calls only.
If Marilee wants to call out, she dials a special access code,
9 for instance, which tells the PBX she wants an outside line.
She is using a different circuit type for outgoing calls. A T1
provided by the CO can contain a multiple of circuit types.
How Do You Set It Up?
The FXO channel cards are set-up in LRB mode as a DPT.
What Do You Order?
For each DID circuit to the PBX you will need one FXO circuit.
The FXO channel cards each have two circuits. So you'll need
to order one circuit for every PBX connection. You will also
require a D/I Mux III.
Megacom WATS
Problem
You have a customer service oriented business. You sell goods
or services over the telephone. Perhaps you run a survey service.
Whatever your reason you've decided to add a WATS trunk to
your communications network in order to save money on outgoing
toll calls. You've contacted the LDC and they will provide
you with a WATS circuit from their switch (Class 4) to your
office.
Solution
Coastcom's 2-Wire FXS in Megacom mode supports WATS services
from the LDC.
How Does It Work?
The Class 4 switch that provides the Megacom service does not
provide EO signaling. Therefore the FXS card in Megacom mode
has to emulate an EO. In other words the FXS provides all the
signaling states to the LDC and to the PBX, that the EO would.
A Megacom circuit has the advantage of directly connecting to
the PSN without local office intervention.

|
Figure v2. Megacom WATS Service
What Actually Occurs?
Coastcom supports 2-Way Megacom services for a variety of
applications. Only the WATS application is being discussed here.
A multitude of signaling types are available. The following situation
assumes ground start operation.
Maryanne owns a telemarketing business. She has a bank of telephones
connected to her PBX. Mario, Vera, and Olga each have a phone
on their desk to make outgoing calls. When they pick up their
phones to make their calls the PBX applies ground to the Megacom
cards. Mario, Vera, and Olga hear a dial tone that is generated
by the LDC
and sent through the Megacom card. When they dial out they are
automatically routed through the LDC bypassing their local EO.
The LDC routes their calls to Marsha, Jan, and Cindy.
The Megacom cards send the outgoing calls to the LDC. Each call
is routed through the PSN to the receiving end's (far end) EO.
Mario calls Marsha, Vera calls Jan, and Olga calls Cindy.
The far end EO rings Marsha's phone line. When she picks up (off-hook),
the off-hook condition is sensed by Marsha's EO. The EO in turn
signals back to the Megacom card to complete the call. When Mario
has completed his survey, he hangs up (on-hook). The on-hook
condition is sensed by the Megacom card. This signals the CO
that the lines are free for further traffic. Vera's and Olga's
calls follow the same pattern.
How Do You Set It Up?
The FXS channel cards are set-up in 2-Way Megacom with ground
start signaling. 2-Way Megacom allows the lines to be used either
as an inbound or outbound circuit. In Megacom WATS applications
only the outbound is used.
What Do You Order?
For each telephone connection you will need one FXS circuit.
The FXS channel cards come with either two circuits per channel
card called a Dual or four circuits per channel card called a
Quad. So you'll need to order one circuit for every telephone
connection. You will also require a D/I Mux III and a ringing
generator.
Megacom 800
Problem
You have a customer service oriented business. You sell goods
or services over the telephone. You want to provide an affordable
method for individuals to contact you. Whatever your reason you've
decided to add an 800 number service to your communications network.
You've contacted the LDC and they will provide you with a T1
trunk of 24 Megacom circuits from their switch (Class 4) to your
office.
Solution
Coastcom's 2-Wire FXS supports Megacom services from the LDC.
How Does It Work?
The Class 4 switch that provides the Megacom service does not
provide EO signaling. Therefore the FXS card in Megacom mode
has to emulate an EO. In other words the FXS provides all the
signaling states to the LDC and to the PBX, that the EO would.
A Megacom circuit has the advantage of directly connecting to
the PSN without local office
intervention.

|
Figure v3. Megacom 800 Service
What Actually Occurs?
Coastcom supports 2-Way Megacom services for a variety of applications.
Only one application is being discussed here; the application
of allowing your clients and customers to call into your location
without having to pay toll charges. This application is commonly
referred to as Megacom 800. Megacom 800 is an inbound toll free
long distance service. A multitude of signaling types are available.
The following situation assumes loop start operation.
Your company is called Ether Etc. and you sell Ether Antennas.
You have a bank of telephones connected to your PBX. Greg, Peter,
and Bobby each have a phone on their desk to accept incoming
calls. Marge, Tanya, and Albert have all seen your advertisements
for Ether Antennas and wish to purchase one. Marge lives in California,
Tanya in Nevada, and Albert in Arizona.
Marge, Tanya, and Albert pick up their phones and call your 800
number. When they dial the special 800 access code their local
COs automatically route their calls to the LDC. The LDC routes
their call to an available circuit on the T1 via the PSN.
The Megacom cards see the incoming calls from the LDC and forwards
them to the PBX. When Greg picks up (off-hook) the PBX establishes
a connection to the Megacom card. The Megacom card then signals
to the LDC to make the call. Because billing for 800 lines is
done in bulk, the near end CO is not required to track the call
and is not involved. Tanya's and Albert's call follow the same
sequence. Tanya is connected to the next available line, in this
case Peter, and Albert is connected to Bobby.
How Do You Set It Up?
The FXS channel cards are set-up in 2-Way Megacom with loop start
signaling.
2-Way Megacom allows the lines to be utilized either as an inbound
or outbound circuit. In Megacom 800 applications only the inbound
is used. The card is automatically set-up for inbound because
it never sees an outbound.
What Do You Order?
For each telephone connection you will need one FXS circuit.
The FXS channel cards come with either two circuits per channel
card called a Dual, or four circuits per channel card called
a Quad. So you'll need to order one circuit for every telephone
connection. You will also require a D/I Mux III and a ringing
generator ringing generator.
2-WAY Megacom
Problem
Your business requires both outgoing WATS services for cost reduction
on sales calls and incoming 800 service for your customer base.
The LDC can combine the services within a single T1. For example,
perhaps you've done a survey of your telephone traffic. You've
found that 50% of your calls are outgoing sales calls and return
calls to customers, and 50% are incoming customer calls. The
LDC will provide you with a T1 and they will provide you with
24 Megacom circuits from their switch (Class 4) to your office.
Solution
Coastcom's 2-Wire FXS in 2-Way Megacom supports both WATS and
800 services from the LDC.
How Does It Work?
The Class 4 switch that provides the Megacom service does not
provide EO signaling. Therefore the FXS card in Megacom mode
has to emulate an EO. In other words the FXS provides all the
signaling states to the LDC and to the PBX, that the EO would.
A Megacom circuit has the advantage of directly connecting to
the PSN without local office intervention.

|
Figure v4. 2-Way Megacom Service
What Actually Occurs?
Coastcom supports 2-Way Megacom services for a variety of applications.
A multitude of signaling types are available. The following situation
assumes ground start operation.
ABC Backhoe Corporation manufactures and sells backhoes through
a national network of dealers. Tyrone is the Communications Manager
for ABC. To cut costs on outgoing calls and to meet the sales
department's requirement for an 800 line he has decided to bring
T1 to the corporate offices. The LDC has sold him on the idea
of Megacom. Tyrone has a limited budget and cannot afford to
replace his analog PBX at this time. He has decided to front-end
the PBX with a T1 channel bank.
ABC has a bank of telephones connected to their PBX. Cliff is
a customer service rep and mostly receives calls from dealers,
Norm is in sales and mostly calls out. They each have a phone
on their desk to make outgoing or to accept incoming calls.
For incoming calls the Megacom cards see the incoming call coming
from the LDC and forwards it to the PBX. When Cliff picks up
(off-hook) the PBX establishes a connection to the Megacom card.
The Megacom card then signals to the LDC.
When Norm picks up his phone to make a call the PBX finds an
available outgoing line and applies ground. He hears a dial tone
generated by the LDC and sent through the Megacom card. When
he dials out he is automatically routed through the LDC bypassing
the local EO. The LDC routes his calls to the appropriate customer.
How Do You Set It Up?
The FXS channel cards are set-up in 2-Way Megacom with ground
start signaling. 2-Way Megacom allows the lines to be utilized
either as an inbound or outbound circuit dependent on the user
traffic.
What Do You Order?
For each telephone connection you will need one FXS circuit.
The FXS channel cards come with either two circuits per channel
card called a Dual, or four circuits per channel card called
a Quad. So you'll need to order one circuit for every telephone
connection. You will also require a D/I Mux III and a ringing
generator.
Caller ID / FXS With
On-Hook Transmission
Problem
Your company provides a substantial amount of customer service.
Many customers are repeat callers. You would like to have a
database on each customer's historic requirements come up automatically
when they call. With Caller ID your PBX can pass the phone
number of the incoming call to a database which in turn will
access your customer's file. How can you get caller ID service
from your T1?
Solution
The 2-Wire FXS card in FXS mode will allow the ID digits to pass
through between rings. Coastcom's 2-Wire FXS channel cards offer
ground start signaling with on-hook transmission support.
How Does It Work?
The FXS card in FXS and on-hook transmission mode works sort
of like a rumor mill. The ID is sent on ahead of the call like
a rumor is sent on ahead of the facts. The ID digits tell you
the phone number of the caller.

|
Figure v5. FXS Connection to PBX
What Actually Occurs?
The FXS channel card will operate in either ground start or loop
start. In this application ground start signaling is recommended.
Jose owns a computer repair service business. Many of his customers
are repeat business and he wants to be able to maintain an amiable
relationship with them. Fortunately his business is booming and
unfortunately he's having trouble keeping track of his customer's
computer systems. He wants his employees to know a repeat customer
and to know their networks when they call in for help.
One of Jose's technicians, Brenda, is free for a call. A customer,
Lyle, calls in for help. Lyle dials the number for Jose's Computer
Service. Lyle's EO routes the call through the PSN to Jose's
business.
The EO sends the first ring followed by the ID digits, using
a method called Frequency Shift Keying (FSK). The FXS, with on-hook
transmission enabled, passes this information to the PBX which
in turn passes it to Jose's computer. The computer processes
the FSK digits in its database.
The EO sends a second ring. Brenda picks up the phone on the
second ring. By now she should have Lyle's file on her terminal.
How Do You Set It Up?
The FXS channel card is set-up in FXS mode with on-hook transmission
and ground start signaling selected.
What Do You Order?
For each telephone connection you will need one FXS circuit.
The FXS channel cards come with either two circuits
per channel card called a Dual, or four circuits per channel
card called a Quad. So you'll need to order one circuit, at
each end, for every telephone connection. You will also require
a D/I Mux III and a ringing generator.
Dial Number Information Service
(DNIS)
Problem
Your business is large enough and you have enough phone traffic
to warrant a voice mail system or you provide timely services
and need paging. Dial Number Information Services is a DID-like
service that can be used with PBXs designed for standard POTS
lines and voice mail or paging management systems. How can
you access DNIS
services with your Coastcom D/I Mux III?
Solution
The 2-Wire FXS card supports two user selectable DNIS modes towards
the network: wink start or delayed dial and loop start or ground
start towards the CPE. For this application you are selecting
two signaling types. One towards the network and one towards
the CPE.
How Does It Work?
The FXS card in DNIS mode works like a protocol converter. To
the CO, it appears to be a DID telephone and to the
PBX it appears to be a standard POTS line from the CO.

|
Figure v6. DNIS Connection to PBX
What Actually Occurs?
The FXS channel card in DNIS mode can be set-up in loop startloop
start or ground startground start towards the PBX and either
delayed dialing or wink start toward the CO.
Alex operates a voice mail service for local physicians called
Med-Exchange. Med-Exchange offers both voice mail and paging
services. Mallory is trying to reach her Orthopedic Surgeon,
Dr. Fox. Today is Saturday and the doctor's
office is closed.
Mallory dials Dr. Fox's emergency number. Mallory's EO routes
the call through the PSN to Med-Exchange. The PBX at Med-Exchange
detects the ringing coming through the FXS card.
The PBX closes the loop and answers the call. A preset buffer
time has been set in the FXS card to allow the 4 digit extension
number through to the PBX. A computer connected to the PBX collects
the digits and offers Mallory the choice of paging Dr. Fox or
leaving him a message. In Mallory's case she chooses to page
him. The computer handles the remainder of the call.
How Do You Set It Up?
The FXS channel card is set-up in DNIS mode. Select ground start
or loop start dependent on your PBX's configuration and wink
start or delayed dialing dependent on the CO's requirements.
What Do You Order?
For each telephone connection you will need one FXS circuit.
The FXS channel cards come with either two circuits per channel
card called a Dual, or four circuits per channel card called
a Quad. So you'll need to order one circuit, at each end, for
every telephone connection. You will also require a D/I Mux III
and a ringing generator.
Digital Switch Upgrade
Problem
Your business has outgrown its analog PBX and it is time to invest
in the latest technology. You want to buy a switch which will
allow for future growth so you purchase a digital switch which
has a T1 interface. However, at this time T1 service is not
required and 4-Wire E&M trunk linestrunk lines from the
CO are already in place.
Solution
Coastcom's 4-Wire E&M channel cards in PLR mode transport
4-Wire E&M trunks from the CO onto a T1 signal to which the
digital switch can communicate.
How Does It Work?
The 4-Wire E&M channel cards in PLR mode behave like a translator.
Messages sent from the CO in the 4-Wire E&M language are
translated into the digital T1 language by the Coastcom D/I Mux
III. Messages sent from the PBX
in the digital T1 language are translated into the 4-Wire E&M
language.

|
Figure v7. 4-Wire to Digital Switch Connections
What Actually Occurs?
Larry's furniture manufacturing and resale company has been around
a long time. Early in its history Larry had invested in his own
analog switch in order to save money and decrease his customer
response time. Recently his analog PBX has been overtaxed and
the technology is obviously dated. He has decided to replace
it with a digital switch. Larry realizes he'll be needing T1
in the near future, but for the present the 4-Wire tie lines
are probably sufficient. Besides Larry prefers a slow transitional
period.
Larry needs to access his digital switch. He has decided a T1
multiplexer will handle the current requirement and in addition
offer him the data services he plans on adding over the next
few years. When it is time to upgrade Larry's carrier service
to T1 he will be prepared with the digital switch and the D/I
Mux III.
An outside caller dials the number to Larry's business. The 4-Wire
E&M trunk accesses the 4-Wire channel card which transports
the signal onto the T1 channel. The digital switch processes
the call with the latest automation available; voice mail and
ring groups are easily set-up. The Coastcom E&M channel cards
support PLR Types I and II
signaling.
How Do You Set It Up?
The 4-Wire E&M channel cards are set up in PLR mode. Any
version of Coastcom 4-Wire E&M will support this application.
The digital switch sees all PLR signaling types in the same manner.
What Do You Order?
The Dual 4-Wire E&M channel cards each have two circuits.
So you will need to order one circuit for every CO connection.
Coastcom has four versions of its 4-Wire E&M channel card;
all versions support this application. You will also require
one D/I Mux III.
Digital Carrier Upgrade
Problem
Your Long Distance Carrier (LDC) is offering inexpensive digital
carrier (T1) rates and installation. Your company wants to
take advantage of these new rates but does not want a major
capital expense at this time. Your existing analog PBX is adequate
for all of your business requirements.
Solution
Coastcom's Dual 4-Wire E&M channel cards transport 4-Wire
E&M trunks from the PBX onto a T1 signal which the CO can
communicate with. T1 from the CO is also converted to 4-Wire
E&M trunks.
How Does It Work?
The 4-Wire E&M channel cards behave like a translator. A
message is sent from the CO in the T1 language and gets translated
into the 4-Wire E&M language by the Coastcom equipment. Messages
sent from the PBX in the 4-Wire E&M language are translated
into the T1 language.
|