IBM F16, Руководство пользователя

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frame transmission has completed. A recipient port is free to reuse a receive buffer
when it receives notification that the frame was transmitted. In the case of multicast,
multiple notifications are required to determine when a receive buffer is freed.
The CMI interfaces for the ASICs are connected inside each ASIC through a
message crossbar, implementing a barrel shift message scheme. Each chip time
slices its output port to each possible destination chip in the switch. If it has a
message to send to a particular destination during the corresponding time slot, the
chip uses the time slot to send the message. Otherwise, the output port lines are
driven to indicate that no message is present.
The time slicing of the output CMI control signals of the ASICs are arranged out of
phase from each other so that each chip’s output port is time sliced to a different
destination chip in any given clock cycle. Messages that display at the input control
signal interface of a given ASIC are also time sliced through each possible source
chip in the switch.
Ports
The 2109 Model F16 supports the following port types:
v Optical ports
v
Ethernet port
v Serial port
Each ASIC in the 2109 Model F16 switch connects up to eight SFP media. SFP
devices are encased in metal to ensure low emissions and high thermal
management. They are hot-swappable and use industry-standard local channel
connectors. Each port provides ISL, loop, and fabric (E, F, and FL respectively) type
connectivity that the 2109 Model F16 senses automatically. It requires no
administration to identify the port type.
Optical ports
For optical ports, the 2109 Model F16 uses SFP fiber-optic transceivers that convert
electrical signals to optical signals (and optical signals to electrical signals).
Each SFP fiber-optic transceiver is capable of transmitting at both 1 and 2 Gbps
speeds and supports:
v
850 nm SWL on multimode fiber-optic cable
v 1310 nm LWL on single-mode fiber-optic cable
v
1550 nm ELWL 5 on single-mode fiber-optic cable
These miniature optical transceivers provide high port density and deliver twice the
port density of standard removable GBIC transceivers.
Ethernet port
The 2109 Model F16 provides a fully IEEE-compliant 10BASE-T or 100BASE-T
Ethernet port for switch management console interface. When a device is
connected to the port, both ends negotiate to determine the optimal speed. The
Ethernet port uses an RJ45 connector. Two LEDs are for the port. One LED
indicates transmit and receive activity and the other LED indicates speed (10 Mbps
or 100 Mbps). You can configure the TCP/IP address for the port from the serial
port.
Serial port
The 2109 Model F16 provides an RS232 serial port. The serial port uses a DB9
connector. The connector is a header pin block on the system board. The
Chapter 1. Introduction
7