Motorola T1/E1 Loss of Clock Signal, Timing Modes, Loopback Timing Mode, Recovered Timing Mode

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Canopy T1/E1 Multiplexer

September 2004

 

T1/E1 Multiplexer FPGA Version 3.4

Loss of Clock Signal

Should the Master port not be able to track the incoming T1/E1 bit stream due to a loss of signal, then the unit will use the Secondary port as the clock source. Once the Master T1 recovers synchronization by locking onto the signal, the unit will revert to using the Master port as the clock source.

Timing Modes

Each T1/E1 interface port that is in use must have clocking configured to avoid potential frame slips. All T1/E1 interface ports have an identical global timing mode. There are two timing modes for the Canopy T1/E1 Multiplexer, namely Loopback and Recovery modes.

Loopback mode: the T1/E1 Transmit clock (transmit from the Canopy T1/E1 Multiplexer) is derived from the incoming Receive clock on the T1/E1.

Recovered mode: the T1/E1 Transmit clock (transmit from the Canopy T1/E1 Multiplexer) is derived from the far-end device’s transmit clock (the far end Canopy T1/E1 Multiplexer Receive clock). In this mode, a buffer is used to accommodate bursts of Ethernet traffic. The buffer is, on average, maintained at a constant level. As the buffer fills, the Transmit clock increases in frequency to avoid overflow. As the buffer empties, the Transmit clock decreases in frequency in order to maintain a constant level.

Note: when the system is set to Recovered Timing Mode, the derived clock is susceptible to Packet Delay Variation (PDV) and may not comply with jitter and wander specifications.

Loopback Timing Mode

Loopback Timing Mode takes the incoming Transmit clock from a network device, such as a PBX, and derives the clock signal from that device for the outgoing Receive clock (PBX receive clock).

Figure 8: Master timing set to Loopback mode

Recovered Timing Mode

Recovered Timing Mode takes the incoming Ethernet bit stream from the BH link and derives the clock signal from the incoming bit stream for the outgoing Receive clock (PBX receive clock).

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Contents Canopy T1/E1 Multiplexer User Guide T1E1Mux-UG-en Issue SeptemberTable of Contents Managing Your Canopy T1/E1 Multiplexers List of Figures List of Tables List of Procedures Searching This User Guide Using this User GuideNew in This Issue Using the Latest InformationAdmonition General Message Label Font Type of InformationVariable width bold Constant width boldSending Feedback Introduction to Canopy T1/E1 MultiplexerGetting Additional Help Canopy T1/E1 Multiplexer with Canopy BHs Ethernet InterfaceRear Panel StandardsIDU Physical Description Rear panel with standard 110-v source power supply Canopy T1/E1 Multiplexer Status Leds LED status indicator descriptionsLED indicator descriptions Front PanelCanopy T1/E1 Multiplexer physical specifications FeaturesSpecifications Physical SpecificationsE1 port specifications Technical SpecificationsT1 port specifications T1 framing specificationsBit Handling Capability Configuration Settings from Canopy FactoryE1 framing specifications Local terminal and control interface specificationsLicense Keys Power AdaptersProduct Labels Functional Description of the Canopy T1/E1 MultiplexerEncoding T1 Channel ModeE1 Channel Mode Channel ModesBinary Eight Zero Substitution Coding Alternate Mark Inversion AMI1 in 15 Requirement AMI High Density Bipolar Order Three Encoding SignalingTiming Master and Secondary Clocks Frequency off-set by clock typeTiming Modes Loss of Clock SignalLoopback Timing Mode Recovered Timing ModeNetwork Timing Scenarios Slave timing set to Recovered modeEthernet Throughput Vlan Support Round‐Trip Packet DelayAlarms Lightning Protection Safety InformationPower Supply Unit ComplianceMounting the Canopy T1/E1 Multiplexer Installation ProceduresPackage Contents Preparing for Installation and SetupPin Designation Direction Connecting the Canopy T1/E1 MultiplexerEnd of procedure T1/E1 port connector pin-outCanopy BH Pin Connecting Power to the Canopy T1/E1 MultiplexerRJ-45 Connector Procedure 2 Connecting cables to T1/E1 unitProcedure 4 Connecting the −48 v DC power source Procedure 3 Connecting the AC adapter +3.3 v DC power sourceIssue the Start-Run-d/setup sequence Initial Configuration ProceduresInstalling Software from the CD‐ROM Procedure 5 Installing Software from the CD-ROMFile drop-down menu in GUI Using EMS Software to Configure the UnitParameter Value Accessing the CLI using a PC + HyperTerminalConfiguring the Canopy T1/E1 Multiplexer using the CLI Procedure 6 Configuring serial portCommand Line Interface window Creating a Login AccountLogging into the System Configuration Procedures Using the CLIChanging the Administrator Password Procedure 7 Changing Administrator password using the CLIEnter get line type Procedure 8 Selecting line type T1 or E1 using the CLISelect Line Type T1 or E1 Action StepsEnter get line code Procedure 9 Configuring line coding using the CLISelect Line Coding Enter set line 1/2/3/4 code HDB3/B8ZS/AMIEnter set canopy port auto negotiation on/off Configure PortsProcedure 10 Configuring the Ethernet ports using the CLI ActionDB 266-399 / 1.8 dB 399-533 / 2.4 dB 533-655 Procedure 11 Configuring the T1 ports using the CLIEnter set secondary clock reference line 1/2/3/4 Enter set clock source loopback/recoveredEnter set master clock reference line 1/2/3/4 Enter set line 1/2/3/4 code HDB3/AMI Procedure 12 Configuring the E1 ports using the CLISet clock source loopback Set clock source recoveredProcedure 13 Configuring timing using the CLI Configure TimingProcedure 14 Logging in using the EMS Configuration Procedures Using the EMSEnd of procedure Login dialogue box File→Command Line Terminal from the EMS Main menu T1/E1 Multiplexer EMS main menu End of procedureChanging the Administrator Password Select Configure T1 Procedure 16 Selecting line type T1 or E1 using the EMSSelect Configure Line Type Procedure 17 Configuring T1 line coding using the EMSProcedure 19 Configuring the Ethernet ports using the EMS Procedure 18 Configuring E1 line coding using the EMSSelect Configure E1 Click ↓ for Secondary Clock Reference Line Procedure 21 Configuring the E1 ports using the EMSClick ↓ for Master Clock Reference Line Procedure 22 Configuring timing using the EMS Remote management overview Remote Management Through Control PortEnter get alarms Procedure 23 Displaying the alarms using the CLISelect the Alarms→T1/E1 Alarms menu Procedure 24 Displaying alarms using the EMSProcedure 26 Resetting the system using the EMS System ResetProcedure 25 Resetting the system using the CLI T1/E1 Loopback Canopy T1/E1 Multiplexer in T1/E1 Loopback modeProcedure 28 Invoking a T1/E1 loopback using the EMS Invoking a T1/E1 Loopback using the CLIInvoking a T1/E1 Loopback Using the EMS Procedure 27 Invoking a T1/E1 loopback using the CLIProcedure 29 Upgrading firmware Measurements from DiagnosticsFirmware Upgrades Comparison of diagnostic measurementsClick Download Fpga revision details screen End of procedureT1/E1 Port Upgrade window License KEY UpgradesInvalid key entry window Software License Terms and Conditions Terms of WarrantyCanopy T1/E1 Multiplexer Obtaining Technical Support Hardware Warranty in U.SInvoking Your Warranty Rights Enter get lan port auto negotiation CLI Commands to GET Status InformationDesired Action Syntax, Response, and Description Enter get canopy port auto negotiationEnter get code line 1/2/3/4 Enter get line 1/2/3/4 lengthEnter get secondary clock reference line Enter get clock sourceEnter get master clock reference line Enter get firmware revision Enter get loopback line 1/2/3/4Regulatory Compliance Information Canadian Compliance Statement TRADEMARKS, Product NAMES, and Service NamesDepartment of Communications Canada European Telecommunications Standards InstituteReferences