Local Customer Transparent Loopback – Provides
a loopback at the NTU in the customer direction (Figure 14). Data is passed transparently to the network side.
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| NTU | TX Data | LTU |
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Figure 14. Local Customer Transparent
Loopback
Remote Customer Transparent Loopback –
Initiated at the NTU and provides a loopback at the LTU in the customer direction (Figure 15). Data is passed transparently to the network side.
NTU | LTU |
TX Data
Figure 15. Remote Customer Transparent
Loopback
Local Customer Nontransparent Loopback – Provides a loopback at the NTU in the customer direction (Figure 16). AIS signal is injected into the network side.
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| NTU | TX AIS | LTU |
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Figure 16. Local Customer Nontransparent
Loopback
Remote Customer Nontransparent Loopback – Initiated at the NTU and provides a loopback at the LTU in the customer direction (Figure 17). AIS signal is injected into the network side.
NTU | LTU |
TX AIS
Figure 17. Remote Customer Nontransparent
Loopback
Local Network Transparent Loopback – Provides a
loopback at the NTU in the network direction (Figure 18). Data is passed transparently to the customer side.
NTU | LTU |
TX Data |
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Figure 18. Local Network Transparent
Loopback
Remote Network Transparent Loopback – Initiated at the NTU and provides a loopback at the LTU in the network direction (Figure 19). Data is passed transparently to the customer side.
NTU | LTU | TX Data |
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Figure 19. Remote Network Transparent
Loopback
Local Network Nontransparent Loopback – Provides a loopback at the NTU in the network direction (Figure 20). AIS signal is injected into the customer side.
NTU | LTU |
TX AIS |
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Figure 20. Local Network Nontransparent
Loopback
Local Network Nontransparent Loopback – Initiated at the NTU and provides a loopback at the LTU in the network direction (Figure 21). AIS signal is injected into the customer side.
NTU | LTU | TX AIS |
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Figure 21. Remote Network Nontransparent
Loopback
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