TSU ESP FAQs

• Can T1 Service Units be used on fractional T1 circuits?
  All ADTRAN T1 Service Units can be used for full or fractional T1 access with one to 24 DS0s or channels mapped to provide the desired T1 bandwidth.
  (ID 60)
  
  
• Can a TSU xx0 be used on a DDS/56k line?
  No. T1 and DDS have different electrical characteristics, including format and signal levels. TSUs (T1 Service Units) are used with T1 circuits and DSUs (Data Service Units) are used with DDS circuits.
  (ID 61)
  
  
• Can I use my TSU on a frame relay circuit?
  Yes, ADTRAN’s TSU xx0 units can be used on frame relay circuits to provide WAN access from an external FRAD (Frame Relay Access Device). These units are not, however, frame relay aware. They simply provide the layer 1 connection between your circuit provider and your DTE equipment. (ie: router, FRAD, etc.)
  (ID 62)
  
  
• Will the TSU xx0 encapsulate frame relay?
  TSU xx0 units can be made frame relay aware when an NxIQ Module (1200255L1) is installed. The NxIQ Module can provide detailed performance monitoring of a frame relay network. Additionally, ADTRAN offers a wide variety of products that provide frame relay encapsulation. The ADTRAN FSU (Frame Relay Service Unit) and ATLAS (ADTRAN's Total Access System) product lines provide full support for frame relay access.
  (ID 63)
  
  
• Is it possible to pre-configure and test ADTRAN’s TSU xx0 units prior to installation?
  Yes, all TSU xx0 units can be pre-configured using front panel access. For testing purposes, a T1 can be simulated by connecting the NETWORK interfaces of the TSU xx0 units using a T1 crossover cable. The T1 crossover connects pins 1 to 4 and 2 to 5 (ie: the Rx pair 1,2 to the Tx pair 4,5).
  (ID 65)
  
  
• How can I determine what alarm I am getting when the alarm indicator is on on my TSU xx0?
  To view the active alarms from the front panel of the TSU xx0 units:
  
  1. Select:1) Status from the main menu.
  2. Then select Active Alarms.
  3. Press ENTER to view the list of currently active alarms.
  
  (ID 68)
  
  
• What is LOS (Loss of Signal)?
  An LOS is an alarm indication that occurs when the CSU does not receive a valid T1 signal (i.e., approximately 1.544 Mbps, nominally 3V peak). A common cause of LOS is an improperly wired cable from the demarcation point to the TSU. Additionally, if excessive zeros are received on an AMI line, LOS can be declared.
  (ID 70)
  
  
• What is Blue/AIS (Alarm Indication Signal) Alarm?
  Blue Alarm, commonly referred to as AIS or Keep Alive, is declared when the CSU is receiving unframed all ones on the network interface indicating an upstream circuit problem, incomplete, or mis-configuration within the telco.
  (ID 71)
  
  
• What is Red Alarm?
  Red Alarm is declared when the CSU cannot synchronize on the framing pattern on the network interface. This may be due to excessive errors on the T1 or an incorrect framing pattern. Red Alarm will be declared if an Out of Frame (OOF) condition exists for 2.5 seconds or more. A common cause of Red Alarm is a mismatch on framing configuration (D4 versus ESF) between the telco and the costomer's CSU.
  (ID 72)
  
  
• Is the TSU ESP flash upgradable?
  Yes, the TSU ESP uses its own flash upgrade program that works only with this unit. The necessary flash software package and detailed instructions regarding the firmware upgrade can be foundon ADTRAN's web site.
  (ID 74)
  
  
• Can I remotely monitor/access the TSU xx0 units?
  There are several ways to remotely monitor/access the TSU xx0 units. They can be accessed using T-Watch PRO or a VT 100 terminal session through the Chain In port located on the rear of the unit. Additionally, Telnet support is provided via a 10BaseT port in "e" products or with the SNMP Agent Module in non "e" products.
  (ID 75)
  
  
• Which units does T-Watch PRO^® support?
  T-Watch Pro, ADTRAN’s PC-based management software, provides a full GUI interface for management of the following units: ESF CSU ACE, CSU RM, TSU, TSU LT, TSU RM, TSU ESP, TSU 100, TSU 100e, TSU 120, TSU 120e, TSU 600, TSU 600e, HSU 100, HSU 600, TDU 110, TDU 120, TDU 120e.
  (ID 76)
  
  
• Which ADTRAN TSU units support SNMP Management?
  ADTRAN’s TSU "e" series products have a built-in SNMP Agent providing SNMP Management from the Ethernet interface. The TSU "e" products include the following: TSU 100e, TSU 120e, TSU 600e. The TSU ESP also supports SNMP when the 10BaseT Module is installed. Additionally, the Agent Module provides SNMP Management when it is installed in the non "e" series of TSU xx0 products.
  (ID 77)
  
  
• What is Red Alarm?
  Red Alarm is declared when the CSU cannot synchronize to the framing pattern on the network interface. This may be due to excessive errors on the T1 or an incorrect framing pattern. Red Alarm will be declared if an Out of Frame (OOF) condition exists for 2.5 seconds or more. A common cause of Red Alarm is a mismatch on framing (D4 versus ESF) between the T1 service provider and the TSU. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 282)
  
  
• What is Blue/AIS (Alarm Indication Signal) Alarm?
  Blue Alarm, commonly referred to as AIS or Keep Alive, is declared when the CSU is receiving unframed all ones on the network interface indicating an upstream circuit problem or an incomplete or misconfiguration within the T1 Circuit. It can originate at the Smart Jack if it does not recognize a valid T1 signal from the CSU (possibly caused by a broken wire pair on pins 4 and 5 or excessive Line Build Out on the CSU), or it may be a result of equipment failure in the Telco network. Typically this alarm points to a problem elsewhere in the T1 circuit, and not at the unit displaying the Blue alarm. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 283)
  
  
• What is LOS (Loss of Signal)?
  An LOS is an alarm indication that occurs when the CSU does not receive a valid T1 signal (i.e., approximately 1.544 Mbps, nominally 3V peak). The wire pair on pins 1 and 2 may be discontinuous or the T1 may not be connected or activated. LOS can also be invoked because of excessive zeros on an AMI circuit. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 284)
  
  
• What is a Yellow alarm?
  Remote Alarm Indication (RAI) is being received at the Network Interface to indicate that the far end is in Red Alarm. It may be inferred that the path from the far end to the near end is good since the RAI is being received successfully. (Note: "far end" refers only to the far end of the local loop, which may extend to the customers' "other" site, or may only go to an intermediate Central Office.) In ESF, the Yellow Alarm is transmitted over the Facility Data Link (FDL). In SF (or D4), it is transmitted inband, by setting the second bit in every DS0 to zero; consequently, it is possible for payload data to mimic the code and cause a "false yellow alarm". Typically this alarm points to a problem elsewhere in the T1 circuit, and not at the unit displaying the yellow alarm. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 285)
  
  
• What is a CRC (Cyclic Redundancy Check) error?
  The "checksum" (actually CRC-6) calculated on the received data does not match the "checksum" calculated by the transmitting equipment. A CRC error indicates that one or more bit errors have occurred on the T1. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 286)
  
  
• What is a BPV (Bipolar Violation) error?
  The CSU detected two consecutive marks of the same polarity in the received AMI signal. (Remember that the T1 signal is always AMI; the line code may be AMI, or AMI with B8ZS.) For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 287)
  
  
• What is a FER (Framing Error)?
  The CSU detected bit errors in the framing bits, but not enough to cause a Red Alarm. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 288)
  
  
• What is a PLL (Phase-Locked Loop) alarm?
  The clock circuit in the CSU is unable to synchronize to the selected clock source. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 289)
  
  
• What is a Code Violation?
  The CSU has detected "CRCs" (if framing is ESF) or "BPVs" (if framing is D4). For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 290)
  
  
• What is a XS0 (Excess Zeros)?
  Excessive zeros have been transmitted from the V.35 interface toward the T1. Actually only a warning, indicating that if the T1 is susceptible to ones density problems (i.e., line code is AMI) then the possibility exists that some circuit element may lose synchronization. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  (ID 291)
  
  
• What is a clock slip?
  The FIFO buffers on the DTE interface have probably over-run (causing the previously processed data to be repeated) because the clock on the Network Interface is of a different frequency from the clock on the DTE interface. This usually indicates multiple clock sources, so verify the timing source for the circuit (i.e. T1, CSU) and that you have the correct Timing Mode selected. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test .
  (ID 292)
  
  
• What is a PLL (Phase-Locked Loop) alarm?
  The clock circuit in the module is unable to synchronize to the clock on the Network Interface. For more information, please see ADTRAN Technical Support Note Troubleshooting an Alarm Condition on ADTRAN TSU Products with Loopback Test.
  
  (ID 293)
  
  
• What is a No EXT Clock alarm?
  The module does not recognize an external transmit clock at the DTE interface, pertinent only when the DTE Transmit Clock is set to External. Confirm that the device connected to the Nx56/64 is indeed providing timing. If so, then confirm that the V.35 cable is supplying clock on pins U and W. The ADTRAN unit must be set for DTE timing under NETWORK configuration.
  (ID 294)
  
  
• What is an Open Loop?
  The module is unable to detect the flow of sealing current, most likely because the CSU/DSU is not connected or the cabling is not correct. For more information, please see ADTRAN Technical Support Note Loopback Adapters and Crossover Cables for T1 and DDS Circuits.
  (ID 295)
  
  
• Default passwords (passcodes) for ADTRAN products.
  Note: Where the product has no default password, Default Password will be N/A.
  
  

  Product	Key sequence (wake up unit)	Default Password
  TSU/TDU XX0	<CTRL>PTT	N/A
  TSU/TDU XX0"e" TSU XX0 "2nd Gen"	<CTRL>PTT	ADTRAN
  TSU/TDU ESP	<CTRL>PTT	adtran (for Telnet only!)
  TSU LT	<CTRL>PTT	N/A
  HSU XX0	<CTRL>PTT	N/A
  T3SU 300	Hit enter a few times	adtran
  Agent card	<CTRL>PTT	ADTRAN
  TSU Router Module/L128/L768/1.5	Hit enter a few times (CTRL-R to refresh screen)	N/A (Hit enter at login prompt)
  Atlas 800/800Plus/810Plus/550	<CTRL> L	Password
  NxIQ	Hit enter a few times	adtran
  TSU IQ/DSU IQ	Hit enter a few times	adtran
  FSU/FSU 5622 Express 5110/5200/5210	Hit enter a few times	adtran
  Smart 16/16e	Hit enter a few times	PASSWORD (if enabled)
  MX2800	Hit enter a few times	adtran

  
  (ID 304)
  
  
• Where can I find the power consumption requirements (for UPS and battery back-up applications) for ADTRAN products?
  The power consumption (in WATTS) can be found under the Product Specifications section of the data sheet for the specific ADTRAN device.
  (ID 326)
  
  
• What is QRSS?
  QRSS stands for Quasi-Random Sequence Signals and is a test pattern run on the T1.
  (ID 335)
  
  
• What does UAS mean?
  UAS is UnAvailable Seconds. This is a count of the number of seconds that a circuit is not available.
  (ID 336)
  
  
• What is the difference between a Line and Payload Loopback?
  Line loopback
loops all of the received data back toward the network. The transmitted data is the identical data that is received and is not reframed or regenerated. This tests right up to the T1 interface of the ADTRAN unit.
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• Payload loopback
performs the same functionality as the line loopback, except the payload loopback sends the received data through the payload so that it is reframed and regenerated out the network. This test also verifies the internal hardware of the local ADTRAN device.
(ID 379)