CMX218S1 MX-COM, Inc., CMX218S1 Datasheet - Page 14

• Manufacturer Part Number: CMX218S1
• Description: ISDN data and telephony protocol engine
• Manufacturer: MX-COM, Inc.

ISDN Data and Telephony Protocol Engine (no X.25)
4.5.3
Outgoing calls are initiated when the POTS port goes off-hook. An ISDN SETUP message is sent to the
network with the Bearer Capability Information Element set to 'Speech'. The dial tone presented by the
network on that ISDN B-channel that was selected by channel mapping (See Section 4.3.6), will be routed to
the POTS port.
When DTMF tones are received from the POTS port, they are sent to the network either as Called Party
Number or Keypad Information Elements. Keypad Information Elements are discussed in Section 4.5.1.
Receipt of a valid DTMF tone will prompt its conversion to IA5 coded digits, as shown in the following table
(IA5 hex digits are in brackets). If the first valid digit to be received is a ‘$’ then the configuration mode is
entered and subsequent digits will be monitored and saved as indicated in Section 4.4.1. If the first tone
received is not a ‘$’ or ‘ ’ (See Section 4.5.1) that digit and all subsequent digits will be passed to the network
in an INFORMATION message as a Called Party Number Information Element. Digits received before the
network has returned the SETUP ACK message are saved. Upon receipt of the SETUP ACK any saved
digits will be transmitted.
The DTMF tone mapping is as shown below:
Once the network has indicated that the full number has been received, no further digits will be sent to the
network. All tones and announcements from the network (e.g. ringing, NU, busy etc) and audio (if the call is
connected) will be routed to the POTS port, until that port goes on-hook.
4.5.4
Once a call is connected to the analog port, whether it was incoming or outgoing, a LED indicator pin is set
high to indicate that the call is connected. See Section 4.9.1 for details of the LED indicator pins. Once the
call is disconnected, either by receipt of a DISCONNECT message from the network or an on-hook indication,
that LED indicator pin is set low.
During a call, if a Recall (i.e. a line break of appropriate length) is received from the POTS port, the CMX218
will start to look for DTMF tones received on the POTS port. Any tones received will then be sent to the
network in ISDN INFORMATION messages, as Keypad Information Elements .
4.5.5
The call is cleared either by the port going on-hook or by the ISDN network. Note that the ISDN B-channel
that was being used is not released until the POTS port has gone on-hook.
MX-COM, Inc
4800 Bethania Station Road, Winston-Salem, NC, 27105-1201, USA
www.mxcom.com tel: [phone] 744 5050 fax: [phone]
All trademarks and service marks are held by their respective companies
Outgoing POTS Calls
Connected Calls
Call Clearing
Low Group
(Hz)
697
770
852
941
$(2A)
1 (31)
4 (34)
7 (37)
1209
2 (32)
5 (35)
8 (38)
0 (30)
1336
14
High Group (Hz)
3 (33)
6 (36)
9 (39)
1477
(23)
2000 Chiron Technology Limited
CMX218 Advance Information
A (not used)
B (not used)
C (not used)
D (not used)
1633
Doc. # 20480215.001
2000 MX-COM, Inc.