Table Of Contents
service-module 56k clock source
service-module 56k data-coding
service-module 56k network-type
service-module 56k remote-loopback
service-module 56k switched-carrier
service-module t1 clock source
service-module t1 remote-alarm-enable
service-module t1 remote-loopback
mdl
To configure the Maintenance Data Link (MDL) message defined in the ANSI T1.107a-1990 specification for the Channelized T3 Interface Processor (CT3IP) in Cisco 7500 series routers, use the mdl interface configuration command . Use the no form of this command to remove the message.
mdl {transmit {path | idle-signal | test-signal} | string {eic | lic | fic | unit | pfi | port |
generator} string}
no mdl {transmit {path | idle-signal | test-signal} | string {eic | lic | fic | unit | pfi | port |
generator} string}Syntax Description
Defaults
No MDL message is configured
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the show controllers t3 command to display MDL information (received strings). MDL information is displayed only when framing is set to C-bit.
Note
MDL is supported only when the DS3 framing is C-bit parity.
Examples
The following examples show several of the mdl commands for the CT3IP in slot 9:
controller t3 9/0/0mdl string eic Router Amdl string lic Test Networkmdl string fic Building Bmdl string unit ABCRelated Commands
media-type
To specify the physical connection on an interface, use the media type interface configuration command. Use the no form of this command to restore the default value.
media-type {aui | 10baset | 100baset | mii}
no media-type {aui | 10baset | 100baset | mii}Syntax Description
aui
Selects a 15-pin physical connection.
10baset
Selects an R-J45 10BaseT physical connection.
100baset
Specifies an RJ-45 100BaseT physical connection.
mii
Specifies a media-independent interface.
Defaults
AUI 15-pin physical connection is the default setting on the Cisco 4000 series.
100BaseT physical connection is the default setting on the Cisco 7000 series and 7200 series.
Command Modes
Interface configuration
Command History
Usage Guidelines
To specify the physical connection on an interface, use the following interface configuration:
•
•
•
Examples
The following example selects an RJ-45 10BaseT physical connection on Ethernet interface 1:
interface ethernet 1 media-type 10basetThe following example specifies a media-independent interface physical connection to Fast Ethernet slot 0, port 1 on the Cisco 7000 or 7200 series:
interface fastethernet 0/1media-type miiThe following example specifies a media-independent interface physical connection to Fast Ethernet slot 0, port adapter 1, port 1 on the Cisco 7500 series:
interface fastethernet 0/1/1media-type miimop enabled
Use the mop enabled interface configuration command to enable an interface to support the Maintenance Operation Protocol (MOP). To disable MOP on an interface, use the no form of this command.
mop enabled
no mop enabledSyntax Description
This command has no arguments or keywords.
Defaults
Enabled on Ethernet interfaces and disabled on all other interfaces.
Command Modes
Interface configuration
Command History
Examples
The following example enables MOP for serial interface 0:
interface serial 0mop enabledRelated Commands
mop sysid
To enable an interface to send out periodic Maintenance Operation Protocol (MOP) system identification messages, use the mop sysid interface configuration command. To disable MOP message support on an interface, use the no form of this command.
mop sysid
no mop sysidSyntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
You can still run MOP without having the background system ID messages sent. This lets you use the MOP remote console, but does not generate messages used by the configurator.
Examples
The following example enables serial interface 0 to send MOP system identification messages:
interface serial 0mop sysidRelated Commands
mop device-code
Identify the type of device sending MOP sysid messages and request program messages.
mop enabled
Enables an interface to support the MOP.
mtu
To adjust the maximum packet size or maximum transmission unit (MTU) size, use the mtu interface configuration command. Use the no form of this command to restore the MTU value to its original default value.
mtu bytes
no mtuSyntax Description
Defaults
Table 1 lists default MTU values according to media type.
Table 1 Default Media MTU Values
Ethernet
1500
Serial
1500
Token Ring
4464
ATM
4470
FDDI
4470
HSSI (HSA)
4470
Command Modes
Interface configuration
Command History
Usage Guidelines
Each interface has a default maximum packet size or maximum transmission unit (MTU) size. This number generally defaults to the largest size possible for that type interface. On serial interfaces, the MTU size varies, but cannot be set smaller than 64 bytes.
Caution
%RSP-3-Restart:cbus complex.
Note
Examples
The following example specifies an MTU of 1000 bytes:
interface serial 1 mtu 1000Related Commands
encapsulation smds
Enables SMDS service on the desired interface.
ip mtu
Sets the MTU size of IP packets sent on an interface.
national bit
To set the E3 national bit in the G.751 frame used by the PA-E3 port adapter, use the national bit interface configuration command. To return to the default E3 national bit, use the no form of this command.
national bit {0 | 1}
no national bitSyntax Description
Defaults
0 national bit
Command Modes
Interface configuration
Command History
Usage Guidelines
The national bit command sets bit 12 in the E3 frame.
To verify the national bit configured on the interface, use the show controller serial EXEC command.
Examples
The following example sets the national bit to 1 on the PA-E3 port adapter in slot 1, port adapter slot 0, interface 0:
interface serial 1/0/0national bit 1Related Commands
Sets the E3 international bit in the G.751 frame used by the PA-E3 port adapter.
Displays information that is specific to the interface hardware.
nrzi-encoding
Use the nrzi-encoding interface configuration command to enable nonreturn-to-zero inverted (NRZI) line-coding format. Use the no form of this command to disable this capability.
nrzi-encoding [mark]
no nrzi-encodingSyntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
10.0
This command was introduced.
11.3
The mark keyword was added for the Cisco 7200 series routers and Cisco 7500 series routers.
Usage Guidelines
All FSIP, PA-8T, and PA-4T+ interface types support nonreturn-to-zero (NRZ) and nonreturn-to-zero inverted (NRZI) format. This is a line-coding format that is required for serial connections in some environments. NRZ encoding is most common. NRZI encoding is used primarily with EIA/TIA-232 connections in IBM environments.
Examples
The following example configures serial interface 1 for NRZI encoding:
interface serial 1nrzi-encodingThe following example configures serial interface 3/1/0 for NRZI mark encoding:
interface serial 3/1/0nrzi-encoding markphysical-layer
To specify the mode of a slow-speed serial interface on a router as either synchronous or asynchronous, use the physical-layer interface configuration command. To return the interface to the default mode of synchronous, use the no form of this command.
physical-layer {sync | async}
no physical-layerSyntax Description
Defaults
Synchronous mode
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies only to low-speed serial interfaces available on Cisco 2520 through 2523 routers.
If you specify the no physical-layer command, you return the interface to its default mode (synchronous).
In synchronous mode, low-speed serial interfaces support all interface configuration commands available for high-speed serial interfaces, except the following two commands:
•
•
When placed in asynchronous mode, low-speed serial interfaces support all commands available for standard asynchronous interfaces.
When you enter this command, it does not appear in the output of more system:running-config and more nvram:startup-config commands because the command is a physical layer command.
Examples
This example changes a low-speed serial interface from synchronous to asynchronous mode:
interface serial 2physical-layer asyncRelated Commands
port
To enable an interface on a PA-4R-DTR port adapter to operate as a concentrator port, use the port interface configuration command. Use the no form of this command to restore the default station mode.
port
no portSyntax Description
This command has no arguments or keywords.
Defaults
Station mode
Command Modes
Interface configuration
Command History
Usage Guidelines
By default, the interfaces of the PA-4R-DTR operate as Token Ring stations. Station mode is the typical operating mode. Use this command to enable an interface to operate as a concentrator port.
Examples
The following example configures the PA-4R-DTR ports to operate in concentrator mode on a Cisco 7000 series router:
router# configure terminalrouter(config)# interface tokenring 3/0/0router(config-if)# portpos flag
To set the SONET overhead bytes in the frame header to meet a specific standards requirement or to ensure interoperability with another vendor's equipment, use the pos flag interface configuration command. To remove the setting of the SONET overhead bytes, use the no form of this command.
pos flag {c2 | j0 | s1s0} value
no pos flag {c2 | j0 | s1s0} valueSyntax Description
Defaults
The default c2 value is 0xCF, and the default sls0 value is 0.
Command Modes
Interface configuration
Command History
11.2 GS
This command was introduced to support the Cisco 120000 series Gigabit Switch Routers.
Usage Guidelines
Use the following values to tell the SONET transmission equipment the payload type:
•
•
•
•
Examples
The following example sets the path signal identifier used to identify the payload content type to ATM on the pos interface in slot 9:
Router(config)# interface pos 9/0Router(config-if)# pos flag c2 0x13Router(config-if)# endRouter#pos framing
To specify the framing used on the POS (Packet-over-SONET) interface, use the pos framing interface configuration command. To return to the default SONET STS-3c framing mode, use the no form of this command.
pos framing {sdh | sonet}
no pos framingSyntax Description
sdh
Selects SDH STM-1 framing. This framing mode is typically used in Europe.
sonet
Selects SONET STS-3c framing. This is the default.
Defaults
SONET STS-3c framing
Command Modes
Interface configuration
Command History
Examples
The following example configures the interface for SDH STM-1 framing:
interface pos 3/0pos framing-sdhno shutdownRelated Commands
pos internal-clock
The clock source (interface) command replaces this command. Refer to the description of clock source for information on transmit clock source.
pos report
To permit selected SONET alarms to be logged to the console for a POS interface, use the pos report interface configuration command. To disable logging of select SONET alarms, use the no form of this command.
pos report {b1-tca | b2-tca | b3-tca | lais | lrdi | pais | plop | prdi | rdool | sd-ber | sf-ber |
slof | slos}
no pos report {b1-tca | b2-tca | b3-tca | lais | lrdi | pais | plop | prdi | rdool | sd-ber | sf-ber |
slof | slos}Syntax Description
Defaults
b1-tca, b2-tca, b3-tca, plop, sf-ber, slof, and slos are reported by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
Reporting an alarm means that the alarm can be logged to the console. Just because an alarm is permitted to be logged does not guarantee that it is logged. SONET alarm hierarchy rules dictate that only the most severe alarm of an alarm group is reported. Whether an alarm is reported or not, you can view the current state of a defect by checking the "Active Defects" line from the show controllers pos command output. A defect is a problem indication that is a candidate for an alarm.
For B1, the bit interleaved parity error report is calculated by comparing the BIP-8 code with the BIP-8 code extracted from the B1 byte of the following frame. Differences indicate that section level bit errors have occurred.
For B2, the bit interleaved parity error report is calculated by comparing the BIP-8/24 code with the BIP-8 code extracted from the B2 byte of the following frame. Differences indicate that line level bit errors have occurred.
For B3, the bit interleaved parity error report is calculated by comparing the BIP-8 code with the BIP-8 code extracted from the B3 byte of the following frame. Differences indicate that path level bit errors have occurred.
PAIS is sent by line terminating equipment (LTE) to alert the downstream path terminating equipment (PTE) that it has detected a defect on its incoming line signal.
PLOP is reported as a result of an invalid pointer (H1, H2) or an excess number of new data flag (NDF) enabled indications.
SLOF is detected when a severely error framing (SEF) defect on the incoming SONET signal persists for 3 milliseconds.
SLOS is detected when an all-zeros pattern on the incoming SONET signal lasts 19(+-3) microseconds or longer. This defect might also be reported if the received signal level drops below the specified threshold.
To determine the alarms that are reported on the interface, use the show controllers pos command.
Examples
The following example enables reporting of SD-BER and LAIS alarms on the interface:
Router(config)# interface pos 3/0/0Router(config-if)# pos report sd-berRouter(config-if)# pos report laisRouter(config-if)# endRouter#Related Commands
interface
The pos keyword configures a POS interface type and enters interface configuration mode.
Displays information about the POS controllers.
pos scramble-atm
To enable SONET payload scrambling on a POS interface, use the pos scramble-atm interface configuration command. To disable scrambling, use the no form of this command.
pos scramble-atm
no pos scramble-atmSyntax Description
This command has no keywords or arguments.
Defaults
Scrambling is disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
SONET payload scrambling applies a self-synchronous scrambler (x^43+1) to the Synchronous Payload Envelope (SPE) of the interface to ensure sufficient bit transition density. Both ends of the connection must use the same scrambling algorithm. When enabling POS scrambling on a VIP2 POSIP on the Cisco 7500 series that has a hardware revision of 1.5 or higher, you can specify CRC 16 only (that is, CRC 32 is currently not supported).
To determine the hardware revision of the POSIP, use the show diag command.
The POS interface on the Cisco 12000 series has no restrictions.
To determine whether scrambling is enabled on the interface, use the show interface pos command or more nvram:startup-config command.
Note
Examples
The following example enables scrambling on the interface:
Router(config)# interface pos 3/0Router(config-if)# pos scramble-atmRouter(config-if)# no shutdownRouter(config-if)# endRouter#Related Commands
pos threshold
To set the BER threshold values of the specified alarms for a POS interface, use the pos threshold interface configuration command. To return to the default setting, use the no form of this command.
pos threshold {b1-tca | b2-tca | b3-tca | sd-ber | sf-ber} rate
no pos threshold {b1-tca | b2-tca | b3-tca | sd-ber | sf-ber} rateSyntax Description
Defaults
The default rate is 6 for b1-tca, b2-tca, b3-tca, and sd-ber. The default is 3 (10e-3) for sf-ber.
Command Modes
Interface configuration
Command History
Usage Guidelines
For B1, the bit interleaved parity error report is calculated by comparing the BIP-8 code with the BIP-8 code extracted from the B1 byte of the following frame. Differences indicate that section level bit errors have occurred.
For B2, the bit interleaved parity error report is calculated by comparing the BIP-8/24 code with the BIP-8 code extracted from the B2 byte of the following frame. Differences indicate that line level bit errors have occurred.
For B3, the bit interleaved parity error report is calculated by comparing the BIP-8 code with the BIP-8 code extracted from the B3 byte of the following frame. Differences indicate that path level bit errors have occurred.
SF-BER and SD-BER are sourced from B2 BIP-8 error counts (as is B2-TCA). However, SF-BER and SD-BER feed into the APS machine and can lead to a protection switch (if APS is configured).
B1-TCA, B2-TCA, and B3-TCA do nothing more than print a log message to the console (if reports for them are enabled).
To determine the BER thresholds configured on the interface, use the show controllers pos command.
Examples
The following example configures thresholds on the interface:
Router(config)# interface pos 3/0/0Router(config-if)# pos threshold sd-ber 8Router(config-if)# pos threshold sf-ber 4Router(config-if)# pos threshold b1_tca 4Router(config-if)# endRouter#Related Commands
pri-group
To specify ISDN Primary Rate Interface (PRI) on a channelized E1 or T1 card on Cisco 7500 series router, use the pri-group controller configuration command. Use the no form of this command to remove the ISDN PRI.
pri-group [timeslots range]
no pri-groupSyntax Description
Defaults
Disabled
Command Modes
Controller configuration
Command History
Usage Guidelines
When you configure ISDN PRI, you must first specify an ISDN switch type for PRI and an E1 or T1 controller.
Examples
The following example specifies ISDN PRI on T1 slot 1, port 0:
isdn switch-type primary-4ess controllers t1 1/0 framing esflinecode b8zs pri-group timeslots 2-6Related Commands
pulse-time
To enable pulsing DTR signal intervals on the serial interfaces, use the pulse-time interface configuration command. Use the no form of this command to restore the default interval.
pulse-time seconds
no pulse-timeSyntax Description
Defaults
0 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
When the serial line protocol goes down (for example, because of loss of synchronization) the interface hardware is reset and the DTR signal is held inactive for at least the specified interval. This function is useful for handling encrypting or other similar devices that use the toggling of the DTR signal to resynchronize.
Examples
The following example enables DTR pulse signals for three seconds on serial interface 2:
interface serial 2 pulse-time 3ring-speed
To set the ring speed for the CSC-1R and CSC-2R Token Ring interfaces, use the ring-speed interface configuration command.
ring-speed speed
Syntax Description
Defaults
16-Mbps operation
Caution
Command Modes
Interface configuration
Command History
Examples
The following example sets a Token Ring interface ring speed to 4 Mbps:
interface tokenring 0 ring-speed 4scramble
To enable scrambling of the payload on the PA-E3 port adapter and the PA-T3 port adapter, use the scramble interface configuration command. To disable scrambling, use the no form of this command.
scramble
no scramble
Syntax Description
This command has no arguments or keywords.
Defaults
Scrambling is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
E3/T3 scrambling is used to assist clock recovery on the receiving end.
Scrambling can prevent some bit patterns from being mistakenly interpreted as alarms by switches placed between the DSUs.
The local interface configuration must match the remote interface configuration. For example, if you enable scrambling on the local port, you must also do the same on the remote port.
To verify that scramble is configured on the interface, use the show controllers serial EXEC command.
Examples
The following example enables scrambling on the PA-E3 port adapter in slot 1, port adapter slot 0, interface 0:
interface serial 1/0/0scrambleRelated Commands
service-module 56k clock rate
To configure the network line speed for a serial interface on a 4-wire, 56/64-kbps CSU/DSU module, use the service-module 56k clock rate interface configuration command. Use the no form of this command to enable a network line speed of 56 kbps, which is the default.
service-module 56k clock rate speed
no service-module 56k clock rate speed
Syntax Description
Defaults
56 kbps
Command Modes
Interface configuration
Command History
Usage Guidelines
The 56-kbps line speed is available in switched mode, which is enabled using the service-module 56k network-type interface configuration command on the 4-wire CSU/DSU. If you have a 2-wire CSU/DSU module, the default is automatically set to switched mode.
The 64-kbps line speed cannot be used with back-to-back digital data service (DDS) lines. The subrate line speeds are determined by the service provider.
The keyword auto enables the CSU/DSU to decipher current line speed from the sealing current running on the network. Use auto only when transmitting over telco DDS lines and the clocking source is taken from the line.
Examples
The following example displays two routers connected in back-to-back DDS mode. However, notice that at first the configuration fails because the auto option is used. Later in the example the correct matching configuration is issued, which is 38.4 kbps.
Router1(config)# interface serial 0Router1(config-if)#service-module 56k clock source internalRouter1(config-if)#service-module 56k clock rate 38.4Router2(config-if)#service-module 56k clock rate autoa1#ping 10.1.1.2Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds:.....Success rate is 0 percent (0/5)Router2(config-if)#service-module 56k clock rate 38.4Router1#ping 10.1.1.2Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 52/54/56 msWhen transferring from DDS mode to switched mode, you must set the correct clock rate, as shown in the following example:
Router2(config-if)#service-module 56k network-type ddsRouter2(config-if)#service-module 56k clock rate 38.4Router2(config-if)#service-module 56k network-type switched% Have to use 56k or auto clock rate for switched mode% Service module configuration command failed: WRONG FORMAT.Router2(config-if)#service-module 56k clock rate auto% WARNING - auto rate will not work in back-to-back DDS.Router2(config-if)#service-module 56k network-type switchedRelated Commands
service-module 56k clock source
To set up the clock source on a serial interface for a 4-wire, 56/64-kbps CSU/DSU module, use the service-module 56k clock source interface configuration command. Use the no form of this command to specify the clocking come from line.
service-module 56k clock source {line | internal}
no service-module 56k clock source {line | internal}
Syntax Description
line
Uses the clocking provided by the active line coming in to the router.
internal
Uses the internal clocking provided by the hardware module.
Defaults
Line clock
Command Modes
Interface configuration
Command History
Usage Guidelines
In most applications, the CSU/DSU should be configured with the clock source line command. For back-to-back configurations, configure one CSU/DSU with the clock source internal command and the other with clock source line command.
Examples
The following example configures internal clocking and transmission speed at 38.4 kbps.
router(config)# interface serial 0router(config-if)# service-module 56k clock source internalrouter(config-if)# service-module 56k clock rate 38.4Related Commands
service-module 56k data-coding
To prevent application data from replicating loopback codes when operating at 64 kbps on a 4-wire CSU/DSU, use the service-module 56k data-coding interface configuration command. Use the no form of this command to enable normal transmission.
service-module 56k data-coding {normal | scrambled}
no service-module 56k data-coding {normal | scrambled}
Syntax Description
normal
Specifies normal transmission of data.
scrambled
Scrambles bit codes or user data before transmission. All control codes such as out of service and out of frame are avoided.
Defaults
Normal data transmission
Command Modes
Interface configuration
Command History
Usage Guidelines
Enable the scrambled configuration only in 64-kbps digital data service (DDS) mode. If the network type is set to switched, the configuration is refused.
If you transmit scrambled bit codes, both CSU/DSUs must have this command configured for successful communication.
Examples
The following example scrambles bit codes or user data before transmission:
router(config)# interface serial 0router(config-if)# service-module 56k clock rate 64router(config-if)# service-module 56k data-coding scrambledRelated Commands
service-module 56k clock rate
Configures the network line speed for a serial interface on a 4-wire, 56/64-kbps CSU/DSU module.
service-module 56k network-type
To transmit packets in switched dial-up mode or digital data service (DDS) mode using a serial interface on a 4-wire, 56/64-kbps CSU/DSU module, use the service-module 56k network-type interface configuration command. Use the no form of this command to transmit from a dedicated leased line in DDS mode.
service-module 56k network-type {dds | switched}
no service-module 56k network-type {dds | switched}Syntax Description
Defaults
DDS is enabled for the 4-wire CSU/DSU.
Switched is enabled for the 2-wire CSU/DSU.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
In switched mode, you need additional dialer configuration commands to configure dial-out numbers. Before you enable the service-module 56k network-type switched command, both CSU/DSUs must use a clock source coming from the line and the clock rate configured to auto or 56 kbps. If the clock rate is not set correctly, this command will not be accepted.
The 2-wire and 4-wire, 56/64-kbps CSU/DSU modules use V.25 bis dial commands to interface with the router. Therefore, the interface must be configured using the dialer in-band command. DTR dial is not supported.
Note
Examples
The following example configures transmission in switched dial-up mode:
router(config)# interface serial 0router(config-if)#service-module 56k clock rate autorouter(config-if)#service-module 56k network-type switchedrouter(config-if)#dialer in-bandrouter(config-if)#dialer string 2576666router(config-if)#dialer-group 1Related Commands
service-module 56k remote-loopback
To enable the acceptance of a remote loopback request on a serial interface on a 2- or 4-wire, 56/64-kbps CSU/DSU module, use the service-module 56k remote-loopback interface configuration command. Use the no form of this command to disable the module from entering loopback.
service-module 56k remote-loopback
no service-module 56k remote-loopbackSyntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
The no service-module 56k remote-loopback command prevents the local CSU/DSU from being placed into loopback by remote devices on the line. The line provider is still able to put the module into loopback by reversing sealing current. Unlike the T1 module, the 2- or 4-wire, 56/64-kbps CSU/DSU module can still initiate remote loopbacks with the no form of this command configured.
Examples
The following example enables transmitting and receiving remote loopbacks:
router(config)# interface serial 0router(config-if)# service-module 56k remote-loopbackRelated Commands
loopback remote (interface)
Loops packets through a CSU/DSU, over a DS3 link or a channelized T1 link, to the remote CSU/DSU and back.
service-module 56k switched-carrier
To select a service provider to use with a 2- or 4-wire, 56/64 kbps dial-up serial line, use the service-module 56k switched-carrier interface configuration command. Use the no form of this command to enable the default service provider.
service-module 56k switched-carrier {att | sprint | other}
no service-module 56k switched-carrier {att | sprint | other}Syntax Description
att
AT&T or other digital network service provider.
sprint
Sprint or other service provider whose network requires echo cancelers.
other
Any other service provider.
Defaults
ATT is enabled on the 4-wire, 56/64-kbps CSU/DSU module.
Sprint is enabled on the 2-wire, switched 56-kbps CSU/DSU module.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
On a Sprint network, echo-canceler tones are sent during call setup to prevent the echo cancelers from damaging digital data. The transmission of echo-canceler tones may increase call setup times by 8 seconds on the 4-wire module. Having echo cancellation enabled does not affect data traffic.
This configuration command is ignored if the network type is DDS.
Examples
The following example configures AT&T as a service provider:
router(config)# interface serial 0router(config-if)# service-module 56k network-type switchedrouter(config-if)# service-module 56k switched-carrier attRelated Commands
service-module 56k network-type
Sends packets in switched dial-up mode or DDS mode using a serial interface on a 4-wire, 56/64-kbps CSU/DSU module.
service-module t1 clock source
To specify the clock source for the fractional T1/T1 CSU/DSU module, use the service-module t1 clock source interface configuration command. Use the no form of this command to return to the default line clock.
service-module t1 clock source {internal | line}
no service-module t1 clock source {internal | line}Syntax Description
Defaults
Line clock
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Examples
The following example sets an internal clock source on serial line 0:
router(config)# interface serial 0router(config-if)# service-module t1 clock source lineRelated Commands
service-module 56k clock source
Sets up the clock source on a serial interface for a 4-wire, 56/64-kbps CSU/DSU module.
service-module t1 data-coding
To guarantee the ones density requirement on an AMI line using the fractional T1/T1 module, use the service-module t1 data-coding inverted interface configuration command. Use the no form of this command to enable normal data transmission.
service-module t1 data-coding {inverted | normal}
no service-module t1 data-coding {inverted | normal}Syntax Description
inverted
Inverts bit codes by changing all 1 bits into 0 bits and all 0 bits into 1 bits.
normal
Requests that no bit codes be inverted before transmission.
Defaults
Normal transmission
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Data inversion is used to guarantee the ones density requirement on an AMI line when using bit-oriented protocols such as High-Level Data Link Control (HDLC), Point-to-Point Protocol (PPP), X.25, and Frame Relay. If the timeslot speed is set to 56 kbps, this command is rejected because line density is guaranteed when transmitting at 56 kbps. Use this command with the 64-kbps line speed.
If you transmit inverted bit codes, both CSU/DSUs must have this command configured for successful communication.
Examples
The following example inverts bit codes using a timeslot speed of 64 kbps:
router(config)# interface serial 0router(config-if)# service-module t1 timeslots all speed 64router(config-if)# service-module t1 data-coding invertedRelated Commands
service-module t1 linecode
Selects the linecode for the fractional T1/T1 module.
service-module t1 timeslots
Defines timeslots that constitute a fractional T1/T1 (FT1/T1) channel.
service-module t1 fdl
To set the fdl parameter to either att or ansi, use the service-module t1 fdl inteface configuration command. Use the no form of this command to ignore the fdl parameter.
service-module t1 fdl {ansi | att}
no service-module t1 fdlSyntax Description
Defaults
Determined by the telephone company.
Command Modes
Interface configuration mode
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2 P.
The default is no service-module t1 fdl. The ansi or att options are determined by your service provider or telephone company.
service-module t1 framing
To select the frame type for a line using the fractional T1/T1 (FT1/T1) module, use the service-module t1 framing interface configuration command. Use the no form of this command to revert to the default, which is Extended Superframe.
service-module t1 framing {esf | sf}
no service-module t1 framing {esf | sf}Syntax Description
esf
Specifies Extended Super Frame as the T1 frame type.
sf
Specifies D4 Super Frame as the T1 frame type.
Defaults
Extended Superframe (ESF)
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Use this command in configurations where the router communicates with FT1/T1 data lines. The service provider determines which framing type, either esf or sf, is required for your circuit.
Examples
The following example enables Super Frame as the FT1/T1 frame type:
service-module t1 framing sfservice-module t1 lbo
To configure the CSU line build out (LBO) on a fractional T1/T1 CSU/DSU module, use the service-module t1 lbo interface configuration command. Use the no form of this command to disable line build out.
service-module t1 lbo {-15 db | -7.5 db | none}
no service-module t1 lbo {-15 db | -7.5 db | none}Syntax Description
-15 db
Decreases outgoing signal strength by 15 dB.
-7.5 db
Decreases outgoing signal strength by 7.5 dB.
none
Transmits packets without decreasing outgoing signal strength.
Defaults
No line build out
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Use this command to decrease the outgoing signal strength to an optimum value for a fractional T1 line receiver. The ideal signal strength should be -15 dB to -22 dB, which is calculated by adding the phone company loss + cable length loss + line build out.
You may use this command in back-to-back configurations, but it is not needed on most actual T1 lines.
Examples
The following example sets the LBO to -7.5 dB:
router(config)# interface serial 0router(config-if)# service-module t1 lbo -7.5dbservice-module t1 linecode
To select the line code for the fractional T1/T1 module, use the service-module t1 linecode interface configuration command. Use the no form of this command to select the default, which is the B8ZS line code.
service-module t1 linecode {ami | b8zs}
no service-module t1 linecode {ami | b8zs}Syntax Description
ami
Specifies alternate mark inversion (AMI) as the line code.
b8zs
Specifies binary 8 zero substitution (B8ZS) as the line code.
Defaults
b8zs
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Configuring B8ZS is a method of ensuring the ones density requirement on a T1 line by substituting intentional bipolar violations in bit positions four and seven for a sequence of eight zero bits. When the CSU/DSU is configured for AMI, you must guarantee the ones density requirement in your router configuration using the service-module t1 data-coding inverted command or the service-module t1 timeslots speed 56 command.
Your T1 service provider determines which line code, either ami or b8zs, is required for your T1 circuit.
Examples
The following example specifies AMI as the line code:
router(config)# interface serial 0router(config-if)# service-module t1 linecode amiRelated Commands
service-module t1 remote-alarm-enable
To generate remote alarms (yellow alarms) at the local CSU/DSU or detect remote alarms sent from the remote CSU/DSU, use the service-module t1 remote-alarm-enable interface configuration command. Use the no form of this command to disable remote alarms.
service-module t1 remote-alarm-enable
no service-module t1 remote-alarm-enableSyntax Description
This command has no arguments or keywords.
Defaults
Remote alarms disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Remote alarms are transmitted by the CSU/DSU when it detects an alarm condition, such as a red alarm (loss of frame) or blue alarm (unframed ones). The receiving CSU/DSU then knows there is an error condition on the line.
With D4 Super Frame configured, a remote alarm condition is transmitted by setting the bit 2 of each time slot to zero. For received user data that has the bit 2 of each time slot set to zero, the CSU/DSU interprets the data as a remote alarm and interrupts data transmission, which explains why remote alarms are disabled by default. With Extended Super Frame configured, the remote alarm condition is signalled out of band in the facilities data link.
You can see if the FT1/T1 CSU/DSU is receiving a remote alarm (yellow alarm) by issuing the show service-module command.
Examples
The following example enables remote alarm generation and detection:
router(config)# interface serial 0router(config-if)# service-module t1 remote-alarm-enableRelated Commands
service-module t1 framing
Selects the frame type for a line using the fractional T1/T1 (FT1/T1) module.
service-module t1 remote-loopback
To specify if the fractional T1/T1 CSU/DSU module enters loopback mode when it receives a loopback code on the line, use the service-module t1 remote-loopback interface configuration command. Use the no form of this command to disable remote loopbacks.
service-module t1 remote-loopback {full | payload} [alternate | v54]
no service-module t1 remote-loopback {full | payload}Syntax Description
Note
Defaults
Full and payload loopbacks with standard-loopup codes
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
You can simultaneously configure the full and payload loopback points. However, only one loopback code can be configured at a time. For example, if you configure the service-module t1 remote-loopback payload alternate command, a payload v54 request cannot be transmitted or accepted.
The no form of this command disables loopback requests. For example, the no service-module t1 remote-loopback full command ignores all full-bandwidth loopback transmissions and requests. Configuring the no form of the command may not prevent telco line providers from looping your router in esf mode, because fractional T1/T1 lines use facilities data link messages to initiate loopbacks.
If you enable the service-module t1 remote-loopback command, the loopback remote commands on the FT1/T1 CSU/DSU module will not be successful.
Examples
The following example displays two routers connected back-to-back through a fractional T1/T1 line:
Router# no service-module t1 remote-loopback fullRouter# service-module t1 remote-loopback payload alternateRouter# loopback remote full%SERVICE_MODULE-5-LOOPUPFAILED: Unit 0 - Loopup of remote unit failedRouter# service-module t1 remote-loopback payload v54Router# loopback remote payload%SERVICE_MODULE-5-LOOPUPFAILED: Unit 0 - Loopup of remote unit failedRouter# service-module t1 remote-loopback payload alternateRouter# loopback remote payload%SERVICE_MODULE-5-LOOPUPREMOTE: Unit 0 - Remote unit placed in loopbackRelated Commands
loopback remote (interface)
Loops packets through a CSU/DSU, over a DS3 link or a channelized T1 link, to the remote CSU/DSU and back.
service-module t1 timeslots
To define timeslots that constitute a fractional T1/T1 (FT1/T1) channel, use the service-module t1 timeslots interface configuration command. Use the no form of this command to resume the default setting (all FT1/T1 timeslots transmit at 64 kbps).
service-module t1 timeslots {range | all} [speed {56 | 64}]
no service-module t1 timeslots {range | all}Syntax Description
Defaults
64 kbps
Command Modes
Interface configuration
Command History
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
This command specifies which timeslots are used in fractional T1 operation and determines the amount of bandwidth available to the router in each FT1/T1 channel.
The timeslot range must match the timeslots assigned to the channel group. Your service provider defines the timeslots that comprise a channel group.
To use the entire T1 line, enable the service-module t1 timeslots all command.
Examples
The following example displays a series of timeslot ranges and a speed of 64 kbps:
service-module t1 timeslots 1-10,15-20,22 speed 64Related Commands
Guest
