OMS 3250

OMS3250Product DescriptionDuring normal working conditions the traffic is transmitted to both switches. In case of fault, thereceiving traffic card selects the traffic from the error-free switch, raises an alarm and theController then disables the faulty switch.The changeover between the two units is hitless.11.1.4 LO-VC Switch UnitIn OMS3250, this unit performs the following functions:• cross connection at VC-4/3/2/12 level;• multiplex section protection (MSP);• Sub-Network Connection Protection;• SDH cross connection at VC-4/3/2/12 level;• SOH and POH processing of the on-board STM-n interfaces;• POH processing of the LO-VC received from the HO-VC switching subsystem;In order to guarantee a high level of availability the Switch Unit can be 1+1 protected.Switch fault detection is achieved through the check of diagnostic messages.During normal working conditions the traffic is transmitted to both switches. In case of fault, thereceiving traffic card selects the traffic from the error-free switch, raises an alarm and theController then disables the faulty switch.11.1.5 Communication/Controller UnitThis unit supports the high-level control of the equipment as defined by G.783, the F and Qinterfaces together with the access to the DCC/GCC channels as requested by G.784 andG798.The Communication/Controller unit contains, in its not-volatile memory, the Softwareexecutables of the cards on the subrack and all the equipment configuration data.11.1.6 Auxiliary UnitThis unit implements the OHA logical block according to G.783.11.2 Internal Distribution Of SignalsThe internal signals can be subdivided in:• traffic signals;• timing signals;• control signals;Issue 1 Copyright – Refer to Page 2 Page 49 of 74