Hardware Description and Reference for Avaya ... - Avaya Support

Circuit packs, channel service units, and power supplies
● timing control, and
● DS1 control.
The TN570 circuit pack also communicates with an EPN’s TN775B Maintenance circuit pack to
send the EPN’s environmental and alarm status to the SPE.
The TN2305 circuit pack or the TN2306 circuit pack replaces the TN570 circuit pack when an
ATM switch replaces the CSS.
The TN570 circuit pack is used in an EPN that is supported by a Survivable Remote Processor
(SRP).
TN572 Switch-Node Clock
The TN572 switch-node clock circuit pack is used with the S8700-series Media Server only.
The TN572 circuit pack distributes the timing signals that synchronize the SN carrier. The
TN572 circuit pack also receives maintenance data.
TN573B Switch-Node Interface
The TN573B Switch Node Interface (SNI) routes circuit, packet, and control messages. The
TN573B circuit pack is an interface that is installed in an SN carrier in a CSS. The TN573B
circuit pack terminates a fiber-optic link from:
● A SNI in an SN carrier to an SNI in another SN carrier
● An EI in a processor port network (PPN), and an EI in an expansion port network (EPN).
One TN573B is used per PN and supports the TN574 DS1 converter circuit pack.
The TN573B circuit pack vintage B and higher provides an interface to the single-mode fiber
optic transceiver. The TN573B also supports the TN1654 circuit pack and TN574 DS1 converter
circuit pack.
TN574 DS1 Converter — T1, 24 Channel
The TN574 is supported. However, it has been replaced by TN1654.
226 Hardware Description and Reference for Avaya Communication Manager