R2 Signaling Examples

This chapter provides examples of R2 signaling that use the following call control elements:

Inpulse rules
Outpulse rules
Host commands and reports

Two examples discuss R2 digit collections on incoming trunks (calls coming into the VCO/4K system); a third example describes R2 digit outpulsing on outgoing trunks (calls originating at the VCO/4K system). Each example begins with a brief explanation of the scenario, followed by a graphic representation of the call flow. These diagrams illustrate system processing and information flow between the VCO/4K and host, and between the VCO/4K and connected equipment (network registers). Direction of the information flow is indicated by arrows under the message data.

Using MFCR2 Outpulse Rule Tokens

MFCR2 outpulse rule tokens include the following tones:

Forward tones—These tones fall into Groups I and II. All Group I and II tones use the ITU R2 forward group tone frequencies. Most of the tones in Group I are used for addressing and identification. Group II tones give information about the origin of the call. Group II tones are also sent by an outgoing MFCR2 service circuits in response to one of the following backward signals:

Change over to the reception of Group B signals.
Send calling party's category.

Backward tones—These tones fall into Groups A and B. The Group A tones acknowledge Group I forward signals. Under certain conditions, Group A tones also acknowledge Group II tones. Group B tones convey the following information to an outgoing MFCR2 register:

The condition of the switch equipment in the incoming exchange.
The condition of the called subscriber's line.

Group B tones are also sent in response to Group II tones once a changeover to the reception of a Group B signal request is successfully completed.

These tones correspond to Category and Fields in the following manner:

OP FIELD [xx] is populated with dialed digits. The first digit in OP FIELD [xx] is always sent first. Additional digits in OP FIELD [xx] are sent in response to an A-1 tone. The Group I-15 tone is sent forward if OP FIELD [xx] is exhausted. Transmission starts again from the top of OP FIELD [xx] in response to an A-2 tone.
IP ANI [xx] is populated by the calling party's A number. The first digit in IP ANI [xx] is sent in response to the second A-6 backward tone.
OP CAT [xx] data is the Group II signal, which indicates the calling party's service class. The single digit in OP CAT [xx] is sent in response to an A-3 backward tone. The Group B backward tone is sent in response to the Group II signal and completes the MFCR2 signaling dialogue.

The Group B tones, as well as tones A-3 and A-6, indicate a terminal status and complete the register signaling dialogue. Pulsed transmission of A-4 indicates a busy state. Receiving tones B-2, B-3, B-4, B-5, A-4, or A-5 cause the system to fail the call attempt.

Example #1—Incoming Call Using Inpulse Rules

Example #1 illustrates a simple R2 digit collection scenario after an incoming seize on the E1 circuit at port address $00 41. A China specific inpulse rule is executed to perform R2 digit collection on this circuit. The rule generates a wink signal when an MFCR2 transceiver is enabled to alert the network register to send the R2 signals.

The inpulse rule performs the following tasks:

Collects an unspecified number of called party number digits and stores them in Field 1. A-1 (send next digit) signals prompt the network register for each new digit. When an I-15 digit is received, the VCO/4K sends an A-6 (send calling party number).
Collects the KA and calling party's number and stores it in the ANI number field. A-1 signals (send next digit) prompt the network register for each new digit. After the digits are received, the VCO/4K sends an A-3 (send KD) digit.
Collects the KD (1 digit) and stores it in Field 3. After the KD is collected, the VCO/4K sends a B-1 (set up speech conditions) digit.

At the end of this example, the VCO/4K establishes speech conditions with the connected equipment (network register) and generates an Inpulse Rule Complete ($DD) report to the host. The processing flow for this example is shown in Figure 4-1. In this example, the China specific inpulse rule for the incoming circuit is defined as inpulse rule #1 (shown below).

Inpulse Rule #1

REP END
WINK ENAB
MFCR2
END CHAR1 6
CLR CHAR1 1
DIGITS 0
IP FIELD 1
END CHAR1 3
CLR CHAR1 1
IP ANI 20
END CHAR1 1
CLR CHAR1 1
DIGITS 1
IP FIELD 3

Refer to the Cisco VCO/4K System Administrator's Guide for more information about MFCR2-specific inpulse rule tokens.

Figure 4-1: Processing Flow for Example #1

Example #2—Incoming Call Using $68 Host Command

Example #2 also illustrates a simple R2 digit collection scenario on an incoming E1 circuit (port address $00 42). However, all R2 digit collections in this scenario are initiated by host command; no inpulse rule processing is used. Three MF Collection Control ($68) commands perform the following actions:

Collect an unspecified number of called party number digits until I-15 digit is received, then send an A-6 to get the KA.
Collect the KA followed by an unspecified number of calling party digits until the I-15 digit is received by sending back A-1, then send back A-3 to get the KD tone.
Collect the KD tone, then send a B-1 (set up speech conditions) digit.

Each digit collection is reported to the host via an MF Digit ($D0) report.

At the end of this example, the VCO/4K establishes speech conditions with the connected equipment (network register). The processing flow for this example is shown in Figure 4-2.

Refer to the Cisco VCO/4K System Administrator's Guide for complete descriptions of the $68 command and $D0 report.

Figure 4-2: Processing Flow for Example #2

Example #3—Outgoing Call

Example #3 describes R2 digit outpulsing on an E1 circuit at port address $00 40. This scenario involves both host command and outpulse rule processing. The host initiates the outpulsing with an Outgoing Port Control ($69) command that populates the digit fields and specifies the outpulse rule to execute (refer to the Cisco VCO/4K Standard Programming Reference and the Cisco VCO/4K Extended Programming Reference for a command description).

The outpulse rule performs the following actions:

Seizes out on the E1 trunk at port address $00 40 and waits for a wink signal (executing the WAIT SUP W preconfigured answer supervision template documented in the Cisco VCO/4K System Administrator's Guide).
Outpulses five digits of the called party number (stored in Field 1) after a wink signal is detected. The VCO responds to A-1 (send next digit) signals that request each new digit.
Outpulses the KA and calling party number stored in the ANI field when an A-6 (send KA) digit is received.
Outpulses the KD digit specified in the rules OP CAT token in response to an A-3. (Here, KD=3, indicating a local calling class.)

This rule is shown below.

Outpulse Rule #1

REP END
SEIZE
WAIT SUP W
OP MFCR2
OP ANI
OP CAT 3
OP FIELD 1

At the end of this example, the VCO/4K establishes speech conditions with the connected equipment (network register) and generates an Outgoing Port Change of State ($DA) report to the host indicating the final KB digit. The processing flow for this example is shown in Figure 4-3.

Refer to the Cisco VCO/4K System Administrator's Guide for more information about OP MFCR2, OP ANI, OP FIELD [xx], and OP CAT [xx] outpulse rule tokens.

Figure 4-3: Processing Flow for Example #3

Table of Contents

R2 Signaling Examples

Using MFCR2 Outpulse Rule Tokens

Example #1—Incoming Call Using Inpulse Rules

Example #2—Incoming Call Using $68 Host Command

Example #3—Outgoing Call