Test access
Overview
Test access, a traditional DCS function, allows the user visibility into any VT1.5/STS-1 signal in the network. Test access aids users in turning up connections and in identifying faults in existing service connections. Alcatel-Lucent 1665 DMX supports three different types of test access. The non-intrusive method simply taps the VT1.5/STS-1 channel as it passes through the system and routes it to an external testing device. The more intrusive mode splits the VT1.5/STS-1 from the incoming signal and sends it to an external testing device. The third form of test access involves using the internal test head, located on the VLF only, to generate and detect Pseudo Random Bit Sequences (PRBSs) on up to 12 STS-1s or 4 STS-3(c) signals. Test access facilitates Alcatel-Lucent 1665 DMX functioning in a DCS application.
PRBS generation/detection
For detailed information regarding internal test access using PRBS, see PRBS generation/detection.
Test access interworking
Alcatel-Lucent 1665 DMX supports interworking with various Test-Head vendors.
Test access rates
Alcatel-Lucent 1665 DMX supports test access sessions at the STS-1, STS3(c) and VT1.5 rates.
Test access modes
Alcatel-Lucent 1665 DMX supports test access sessions in the following modes:
MONE mode
The MONE mode is used to monitor the E Tributary input signal of a one-way cross-connection or an idle E Tributary input signal (no cross-connection).
The following figure shows an example of the MONE mode used to monitor the E Tributary input signal of 2 separate one-way cross-connections.
If the F Tributary is entered, the F Tributary must be the destination of a one-way cross-connection that has the E Tributary as the source. If the E Tributary is part of a one-way multicast cross-connection, entering the F Tributary is optional. The system automatically retrieves the other end. The E Tributary or F Tributary can not be on an Ethernet circuit pack.
SPLTE mode
The SPLTE mode is used to test the E Tributary signal.
The following figure shows an example of the SPLTE mode used to test the E Tributary signal of 2 separate one-way cross-connections.
The E Tributary signal is split from the F Tributary signal. AIS is transmitted on the outgoing F Tributary signal. and the incoming F Tributary signal is terminated. If more than one independent one-way cross-connection exists to the E Tributary, the SPLTE mode is denied. The E Tributary can also be idle (no cross-connection). The E Tributary or F Tributary cannot be on an Ethernet circuit pack.
STS-1 test access matrix
The table below provides all the STS-1 test access specifications supported by Alcatel-Lucent 1665 DMX. The numbers in the table below represent the software release number in which that configuration is first supported. Test access on STS-3(c) signals is only supported in SPLTA, SPLTE, and MONE modes using the internal test head located in the VLF Main packs for PRBS generation/detection
Table 5-7: STS-1 test access
|
TATRIBs | ||||||||
|---|---|---|---|---|---|---|---|---|
|
Slot |
Signal |
A–D slots (elect) |
||||||
|
DS3/EC1 |
TMUX |
OC-3 |
OC-12 |
OC-48 | ||||
|
LNW16 LNW19B LNW20 |
LNW18 LNW20 |
LNW37 LNW45 LNW55 |
LNW49 LNW55 |
LNW31 LNW55 LNW62 | ||||
|
ETRIB and FTRIB |
A–G |
DS3/EC1 |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | |
|
A–G |
OC-3/12/ 48, 6 |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | ||
|
Thru XC |
BLSR |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | ||
|
UPSR |
R5.1 |
Deny |
R5.1 |
R5.1 |
R5.1 | |||
|
A–G |
DS3/EC1 |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | ||
|
A–G |
OC-3/12/ 48, 6 |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | ||
|
TMUX 8 |
R7.0 |
R7.0 |
R7.0 |
R7.0 |
R7.0 | |||
|
A–D |
DS3/EC1 |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | ||
|
A–G |
OC-3/12/ 48, 6 |
R4.0 |
Deny |
R4.0 |
R5.1 |
R4.0 | ||
|
OC-192 7 (M1/M2) hairpin to: |
M1/M2 |
OC-192 |
R7.0 |
R7.0 |
R7.0 |
R7.0 |
R7.0 | |
Notes:
TATRIB1 and TATRIB2 are always connected to the same optical interface.
Intended for network-connected testheads where the tributary under test is in one NE and the test head is connected to a different NE.
Test Access of locked cross-connections restricted to electrical TATRIBs
Test Access of UPSR Dual Ring Interworking cross-connections is not supported
Test access of low-speed BLSR cross-connections is not supported
All high-speed Main OLIUs allow the STS-1 test access modes specified in this table. Hairpins from high-speed Main interfaces to other high-speed Main interfaces only allowed on the LNW59 because it is the only Main OC-192 pack with multiple ports. Generation and detection of PRBS only supported on the LNW59.
TMUX test access in the G slots only supported using the LNW20 in portless mode.
VT1.5 test access matrix
The "dual tatrib" modes (MONEF and SPLTEF) of VT test access are not possible when the system is equipped with small/medium VT fabric Main OLIUs. This applies to all systems equipped with OC3 or OC12 Main OLIUs.
The table below provides all the VT1.5 test access specifications supported by Alcatel-Lucent 1665 DMX. The numbers in the table below indicate the software release number in which that configuration is first supported.
Table 5-8: VT1.5 test access
|
TATRIBs | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Slot |
Signal |
A–D slots |
|||||||
|
EC1 |
TMUX |
DS1/E1 |
OC-3 |
OC-12 |
OC-48 | ||||
|
LNW16 LNW19B LNW20 |
LNW18 LNW20 |
LNW7 LNW8 LNW801 |
LNW37 LNW45 LNW55 |
LNW49 LNW55 |
LNW31 LNW55 LNW62 | ||||
|
ETRIB and FTRIB |
A–D |
DS3/EC1 3 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |
|
TMUX |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |||
|
DS1/E1 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |||
|
A–G |
OC-3/12/ 48 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | ||
|
A–D |
DS3/EC1 3 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | ||
|
TMUX |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |||
|
DS1/E1 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |||
|
A–G |
OC-3/12/ 48 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | ||
|
A–D |
DS3/EC1 3 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | ||
|
TMUX |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |||
|
DS1/E1 6 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | |||
|
A–G |
OC-3/12/ 48 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | ||
|
TMUX (LNW20 portless only) |
R7.0 |
R7.0 |
R7.0 |
R7.0 |
R7.0 |
R7.0 | |||
|
M1/M2 |
OC-12/ 48/192 8 |
R4.0 |
R4.0 |
R4.0 |
R4.0 |
R5.1 |
R4.0 | ||
Notes:
TATRIB1 and TATRIB2 are always connected to the same optical interface.
Intended for unprotected interfaces to locally-connected testheads only; Network-connected testheads - Future\
Large VT Fabric Mains Only; restrictions apply for any OC3/12 Main OLIU.
Test Access of locked cross-connections restricted to electrical TATRIBs
Test Access of UPSR Dual Ring Interworking cross-connections not supported
Test access of low-speed BLSR cross-connections not supported
All high-speed Main OLIUs allow the STS-1 test access modes specified in this table. Generation and detection of PRBS only supported on the LNW59, LNW82, and LNW504.
PRBS generation/detection
Test access using PRBS generation/detection via the internal test head on the VLF Main allows the user to test network, NE, and facility performance/integrity without an external test head. VLF Mains contain an internal test head that can generate and detect errors in Pseudo Random Bit Sequences (PRBSs). This capability is not meant to wholly eliminate the use of external equipment for tests, but can be used for expediency, less complicated tests, and where non-manual set-up is advantageous. PRBS enabled test access involves initiating test access, inserting a test signal (i.e. a PRBS) generated internal to the NE, and/or monitoring a received test signal internal to the NE. PRBS generation/detection is supported on STS1 and STS3c tributaries.
Alcatel-Lucent 1665 DMX allows up to 12 test access sessions at a time and for a mix of test access sessions that specify tatrib(s) and test access sessions to the internal test head within the 12 allowed sessions. The internal test head hardware supports signal generation on up to 12 STS1s, and signal detection on up to 12 STS1s. The generators and detectors are separately allocated. Internal test access is supported on STS3c signals; requests using the tatrib parameter(s) are denied. When a generator or detector is allocated to an STS3c session, it uses 3 of the 12-STS1 capacity, and that 3 generators or detectors on the STS3c boundary must be available.
Generation and detection functionality
PRBS Generation is totally independent of detection and error counting. The only similarity is that they both occur in the context of test sessions. One session may produce a signal that is detected/measures by a different session (in the same, or different Alcatel-Lucent 1665 DMX).
While measurement/monitoring of incoming PRBS signals is occurring, the shelf collects total measurement session counts and PM-style counts, including 15-minute and day bins tied to the time-of-day clock. The bins are retrieved by the user on-demand and are freed when the test access session (not the measuring session) ends. Bins survive a shelf restart and are initialized by a power-up of the shelf.
Modes allowed for PRBS functionality
Alcatel-Lucent 1665 DMX supports PRBS enabled internal test access sessions in the following modes:
Alcatel-Lucent 1665 DMX must be in MONE mode to initiate a PRBS enabled test access session. The mode must then be changed to either SPLTE or SPLTA in order to support the configurations detailed below.
Testing to a far-end loopback
This configuration involves a SPLTE test session at a single Alcatel-Lucent 1665 DMX node, with generation and detection at the same node. The tributary under test must be cross-connected.
Alcatel-Lucent 1665 DMX is first set to MONE mode and then changed to SPLTE mode. AIS is inserted into the tributary being tested until the PRBS generator is set to generate and insert a bit sequence on that tributary. The Generator and detector are then connected to the tributary. The PRBS is inserted into the tributary, sent to and looped back at the far-end, and then monitored for errors by the PRBS detector located on the VLF Main circuit packs.
Head-to-head testing
This configuration involves generating a signal at one node (node A), and monitoring the signal at a different node (node B). The tributary under test at node A must be cross-connected. The tributary at node B may or may not be cross-connected.
Node A and B are first set to MONE mode, but while the generator on Node A is then connected to the tributary and the detector on Node B is also connected to the tributary. The PRBS signal originating at Node A is monitored for errors by the PRBS detector located on the VLF Main circuit packs in Node B.
Total network testing
This configuration involves a SPLTA test session at a single Alcatel-Lucent 1665 DMX node, with generation and detection at the same node. The tributary under test must be cross-connected.
Alcatel-Lucent 1665 DMX is first set to MONE mode and then changed to SPLTA mode. AIS is inserted into the tributary being tested until the PRBS generator is set to generate and insert a bit sequence on that tributary. The generator and detector are then connected to the tributary. A PRBS is inserted into the tributary, sent to and looped back at the far-end, passed-through Node A and sent to a far-end node in the other direction where it is looped back to Node A. The PRBS signal is then monitored for errors by the PRBS detector located on the VLF Main circuit packs in Node A before the tributary is terminated.