Overview
X.21 interfaces provide synchronous operation between data communication equipment (DCE) and data terminal equipment (DTE) on public data networks.
V.35 interfaces provide synchronous operation between DCE and DTE for data communication over the telephone network. Although the V.35 standard is considered obsolete and is no longer supported by ITU-T, many V.35 connections still exist in telephone networks.
ERX-7xx models and the ERX-1410 router support the X.21/V.35 line module and I/O module. The ERX-1440 router does not support the X.21/V.35 line module and I/O module.
The X.21/V.35 interface includes an HDLC layer. You can configure other protocols over this HDLC layer.
X.21/V.35 line modules pair with I/O modules to provide particular capabilities and connections.
For complete module details, see Table 49, the E-series Module Guide, and the JUNOSe Physical Layer Configuration Guide.