Setup guide

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Cisco 6400 Software Setup Guide
OL-1183-04
Chapter2 Basic NSP Configuration
Network Clocking
Cross-connect OAM-state: Not-applicable
Encapsulation: AAL5ILMI
Threshold Group: 6, Cells queued: 0
Rx cells: 35, Tx cells: 35
Tx Clp0:35, Tx Clp1: 0
Rx Clp0:35, Rx Clp1: 0
Rx Upc Violations:0, Rx cell drops:0
Rx pkts:16, Rx pkt drops:0
Rx connection-traffic-table-index: 3
Rx service-category: VBR-RT (Realtime Variable Bit Rate)
Rx pcr-clp01: 424
Rx scr-clp01: 424
Rx mcr-clp01: none
Rx cdvt: 1024 (from default for interface)
Rx mbs: 50
Tx connection-traffic-table-index: 3
Tx service-category: VBR-RT (Realtime Variable Bit Rate)
Tx pcr-clp01: 424
Tx scr-clp01: 424
Tx mcr-clp01: none
Tx cdvt: none
Tx mbs: 50
AAL5 statistics:
Crc Errors:0, Sar Timeouts:0, OverSizedSDUs:0
BufSzOvfl: Small:0, Medium:0, Big:0, VeryBig:0, Large:0
Switch#
Network Clocking
This section describes the network clocking configuration of the Cisco 6400. Each port has a transmit
clock that is derived from the receive data. The transmit clock can be configured for each port in one of
the following ways:
• Free-running—The transmit clock on the interface is derived from the port adapter's local oscillator,
if one exists. If the port adapter does not have a local oscillator, the oscillator from the NSP is used.
In this mode, the transmit clock is not synchronized with any receive clocks in the system. This
mode should be used only if synchronization is not required, as in some LAN environments.
• Network derived—The transmit clock is derived from the highest priority configured network clock
source—the system clock (the local oscillator on the NSP), the Building Integrated Timing Supply
(BITS), or the public network.
• Loop-timed—The transmit clock is derived from the clock source received on the same interface.
This mode can be used when connecting to a device with a very accurate clock source.
Any NLC in a Cisco 6400 chassis capable of receiving and distributing a network timing signal can
propagate that signal to any similarly capable module in the chassis. Using the network-clock-select
global configuration command, you can cause a particular port in a Cisco 6400 chassis to serve as the
primary reference source (PRS) for the entire chassis or for other devices in the networking environment.
In other words, you can designate a particular port in a Cisco 6400 chassis to serve as a “master clock”
source for distributing a single clocking signal throughout the chassis or to other network devices. This
reference signal can be distributed wherever needed in the network and can globally synchronize the
flow of constant bit rate (CBR) data.
For more information on network clocking, see the chapter “Initially Configuring the ATM Switch” in
the ATM Switch Router Software Configuration Guide.