signal
To specify the type of signaling for a voice port, use the signal command in voice-port configuration mode. To reset to the default, use the no form of this command.
Foreign Exchange Office (FXO) and Foreign Exchange Station (FXS) Voice Ports
signal {groundstart | loopstart [live-feed]}
no signal {groundstart | loopstart}
Ear and mouth (EandM) Voice Ports
signal {delay-dial | immediate | lmr | wink-start}
no signal {delay-dial | immediate | lmr | wink-start}
Centralized Automatic Message Accounting (CAMA) Ports
signal {cama {kp-0-nxx-xxxx-st | kp-0-npa-nxx-xxxx-st | kp-2-st | kp-npd-nxx-xxxx-st | kp-0-npa-nxx-xxxx-st-kp-yyy-yyy-yyyy-st} | groundstart | loopstart}
no signal {cama {kp-0-nxx-xxxx-st | kp-0-npa-nxx-xxxx-st | kp-2-st | kp-npd-nxx-xxxx-st | kp-0-npa-nxx-xxxx-st-kp-yyy-yyy-yyyy-st} | groundstart | loopstart}
Syntax Description
groundstart |
Specifies the use of groundstart signaling. Used for FXO and FXS interfaces. Groundstart signaling allows both sides of a connection to place a call and to hang up.
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loopstart |
Specifies the use of loop start signaling. Used for FXO and FXS interfaces. With loopstart signaling, only one side of a connection can hang up. This is the default setting for FXO and FXS voice ports.
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live-feed |
(Optional) Enables an MOH audio stream from a live feed to be directly connected to the router through an FXO port. |
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delay-dial |
The calling side seizes the line by going off-hook on its E-lead. After a timing interval, the calling side looks at the supervision from the called side. If the supervision is on-hook, the calling side starts sending information as dual tone multifrequency (DTMF) digits; otherwise, the calling side waits until the called side goes on-hook and then starts sending address information. Used for E&M tie trunk interfaces. |
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immediate |
The calling side seizes the line by going off-hook on its E-lead and sends address information as DTMF digits. Used for E&M tie trunk interfaces. |
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lmr |
Specifies the use of Land Mobile Radio signaling. |
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wink-start |
The calling side seizes the line by going off-hook on its E-lead then waits for a short off-hook "wink" indication on its M-lead from the called side before sending address information as DTMF digits. Used for E&M tie trunk interfaces. This is the default setting for E&M voice ports. |
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cama |
Selects and configures the port for 911 calls. |
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kp-0-npa-nxx-xxxx-st |
10-digit transmission. The E.164 number is fully transmitted. |
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kp-0-npa-nxx-xxxx-st-kp-yyy-yyy-yyyy-st |
Supports CAMA Signaling with ANI/Pseudo ANI (PANI). |
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kp-0-nxx-xxxx-st |
7-digit automatic number identification (ANI) transmission. The Numbering Plan Area (NPA) or area code is implied by the trunk group and is not transmitted. |
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kp-2-st |
Default transmission when the CAMA trunk cannot get a corresponding Numbering Plan Digit (NPD) digit in the lookup table, or when the calling number is fewer than ten digits in length. (NPA digits are not available.) |
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kp-npd-nxx-xxxx-st |
8-digit ANI transmission, where the NPD is a single multifrequency (MF) digit that is expanded into the NPA. The NPD table is preprogrammed in the sending and receiving equipment (on each end of the MF trunk); for example: 0 = 415, 1 = 510, 2 = 650, 3 = 916 05550100 = (415) 555-0100, 15550100 = (510) 555-0100, and so on. NPD range is from 0 to 3. |
Command Default
FXO and FXS interfaces: loopstart E&M interfaces: wink-start CAMA interfaces: loopstart
Command Modes
Voice-port configuration (config-voiceport)
Command History
Release |
Modification |
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11.3(1)T |
This command was introduced on the Cisco 3600 series. |
12.2(11)T |
This command was modified to support ANI transmission. |
12.3(4)XD |
The lmr keyword was added. |
12.3(7)T |
This command was integrated into Cisco IOS Release 12.3(7)T. |
12.3(14)T |
This command was implemented on the Cisco 2800 series and Cisco 3800 series. |
12.4(9)T |
The kp-0-npa-nxx-xxxx-st-kp-yyy-yyy-yyyy-st keyword was added to support CAMA Signaling with ANI/Pseudo ANI (PANI). |
12.4(11)XJ |
The live-feed keyword was added. |
12.4(15)T |
The live-feed keyword was integrated into Cisco IOS Release 12.4(15)T. |
Usage Guidelines
This command applies to analog voice ports only. A voice port must be shut down and then activated before the configured values take effect.
For an E&M voice port, this command changes only the signal value for the selected voice port.
For an FXO or FXS voice port, this command changes the signal value for both voice ports on a voice port module (VPM). If you change the signal type for an FXO voice port on Cisco 3600 series routers, you need to move the appropriate jumper in the voice interface card of the voice network module. For more information about the physical characteristics of the voice network module, see the installation documentation that came with your voice network module.
Some PBXs miss initial digits if the E&M voice port is configured for immediate start signaling. Immediate start signaling should be used for dial pulse outpulsing only and only on circuits for which the far end is configured to accept digits within a few milliseconds of seizure. Delay dial signaling, which is intended for use on trunks and not lines, relies on the far end to return an off-hook indication on its M-lead as soon as the circuit is seized. When a receiver is attached, the far end removes the off-hook indication to indicate that it is ready to receive digits. Delay dial must be configured on both ends to work properly. Some non-Cisco devices have a limited number of DTMF receivers. This type of equipment must delay the calling side until a DTMF receiver is available.
To specify which VIC-2CAMA ports are designated as dedicated CAMA ports for emergency 911 calls, use the signal cama command. No two service areas in the existing North American telephony infrastructure supporting E911 calls have identical service implementations, and many of the factors that drive the design of emergency call handling are matters of local policy and therefore outside the scope of this document. Local policy determines which ANI format is appropriate for the specified Physical Service Access Point (PSAP) location.
The following four types of ANI transmittal schemes are based on the actual number of digits transmitted toward the E911 tandem. In each instance, the actual calling number is proceeded with a key pulse (KP) followed by an information (I) field or a NPD, which is then followed by the ANI calling number, and finally is followed by a start pulse (ST), STP, ST2P, or ST3P, depending on the trunk group type in the PSTN and the traffic mix carried.
The information field is one or two digits, depending on how the circuit was ordered originally. For one-digit information fields, a value of 0 indicates that the calling number is available. A value of 1 indicates that the calling number is not available. A value of 2 indicates an ANI failure. For a complete list of values for two-digit information fields, see SR-2275: Telcordia Notes on the Networks at www.telcordia.com .
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7-digit transmission (kp 0 nxx xxxx st ):
The calling phone number is transmitted, and the NPA is implied by the trunk group and not transmitted.
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8-digit transmission (KP npd nxx xxxx st ) :
The I field consists of single-digit NPD-to-NPA mapping. When the calling party number of 415-555-0122 places a 911 call, and the Cisco 2600 series or Cisco 3600 series has an NPD (0)-to-NPA (415) mapping, the NPA signaling format is received by the selective router at the central office (CO).
![]() Note |
NPD values greater than 3 are reserved for signifying error conditions. |
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10-digit transmission (kp 0 npa nxx xxxx st)
The E.164 number is fully transmitted.
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20-digit transmission (kp-0-npa-nxx-xxxx-st-kp-yyy-yyy-yyyy-st ):
Twenty digits support (two 10 digit numbers) on FGD-OS in the following format, KP+II+10 digit ANI+ST+KP+7/10 digit PANI+ ST
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kp-2-st transmission (kp -2 -st ):
kp-2-st transmission is used if the PBX is unable to out-pulse the ANI. If the ANI received by the Cisco router is not as per configured values, kp-2-st is transmitted. For example, if the voice port is configured for out-pulsing a ten-digit ANI and the 911 call it receives has a seven-digit calling party number, the router transmits kp-2-st.
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Emergency 911 calls are not rejected for an ANI mismatch. The call establishes a voice path. The E911 network, however, does not receive the ANI. |
Examples
The following example configures groundstart signaling on the Cisco 3600 series as the signaling type for a voice port, which means that both sides of a connection can place a call and hang up:
voice-port 1/1/1
signal groundstart
The following example configures a ten-digit ANI transmission:
Router(config)#
voice-port 1/0/0
Router(config-voiceport)# signal cama kp-0-npa-nxx-xxxx-st
The following example configures 20-digit CAMA Signaling with ANI/Pseudo ANI:
Router(config-voiceport)# signal cama KP-0-NPA-NXX-XXXX-ST-KP-YYY-YYY-YYYY-ST