Configuring Serial Interfaces
Devices that communicate over a serial interface are divided into two classes: data terminal equipment (DTE) and data circuit-terminating equipment (DCE). Juniper Networks Serial Physical Interface Cards (PICs) have two ports per PIC and support full-duplex data transmission. These PICs support DTE mode only. On the Serial PIC, you can configure three types of serial interfaces:
- EIA-530—An Electronics Industries Alliance (EIA) standard for the interconnection of DTE and DCE using serial binary data interchange with control information exchanged on separate control circuits.
- V.35—An ITU-T standard describing a synchronous, physical layer protocol used for communications between a network access device and a packet network. V.35 is most commonly used in the United States and in Europe.
- X.21—An ITU-T standard for serial communications over synchronous digital lines. The X.21 protocol is used primarily in Europe and Japan.
The following standards apply to serial interfaces:
- TIA/EIA Standard 530, High-Speed 25-Position Interface for Data Terminal Equipment and Data Circuit-Terminating Equipment, defines the signals on the cable and specifies the connector at the end of the cable.
- TIA/EIA Standard 232, Interface between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, describes the physical interface and protocol for serial data communication.
- ITU-T Recommendation V.35, Data Transmission at 48 kbit/s Using 60-108 kHz Group Band Circuits. Note that the Juniper Networks Serial PIC supports V.35 interfaces with speeds higher than 48 kilobits per second.
- ITU-T Recommendation X.21, Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment for Synchronous Operation on Public Data Networks.
There are no serial interface-specific logical properties. For information about general logical properties that you can configure, see Configuring Logical Interface Properties.
To configure serial physical interface properties, include the
serial-optionsstatement for the J-series routing platform at the[edit interfacesse-pim/0/port]hierarchy level or at the[edit interfaces se-fpc/pic/port]hierarchy level for M-series and T-series routing platforms:[edit interfaces se-fpc/pic/port]serial-options{clock-raterate;clocking-mode(dce | dte | loop);control-polarity(negative | positive);cts-polarity(negative | positive);dcd-polarity(negative | positive);dce-options{control-signal(assert | de-assert | normal);cts(ignore | normal | require);dcd(ignore | normal | require);dsr(ignore | normal | require);dtrsignal-handling-option;ignore-all;indication(ignore | normal | require);rts(assert | de-assert | normal);tm(ignore | normal | require);}dsr-polarity(negative | positive);dte-options{control-signal(assert | de-assert | normal);cts(ignore | normal | require);dcd(ignore | normal | require);dsr(ignore | normal | require);dtrsignal-handling-option;ignore-all;indication(ignore | normal | require);rts(assert | de-assert | normal);tm(ignore | normal | require);}dtr-circuit(negative | positive);dtr-polarity(negative | positive);encoding(nrz | nrzi);idle-cycle-flagflag;indication-polarity(negative | positive);line-protocolprotocol;loopbackmode;rts-polarity(negative | positive);tm-polarity(negative | positive);transmit-clockinvert;}This chapter discusses configuration of the following serial interface properties: