Plugs

Both SC and LC plugs also come as Duplex, which are simply two plugs stuck together.

SC vs. LC

• SC is from the mid 80 (Nippon Telegraph and Telephone), defined in TIA-568-A since 1991
• LC is from the early 2000 (Lucent Technologies) defined in IEC 61754-20 since 2002
  • Slow start due to high licensing costs
• LC is half the size of SC
• Different latching mechanisms
• Above that basically the same

SFP Modules & Interfaces

Fibre networks use two different wavelenghts/colours for the up- and downstream communication. In this context the downstream (OLT->ONT) communication runs on 1490nm (ONT->OLT) and the upstream communication on 1310nm. The perspective here is from the provider to the customer. As such communication from the OLT to the ONT is called downstream, the ONT to OLT communication is the upstream. This fact directly results in the necessity of different SFP modules or interfaces on both sides of the communication. The Up side has a 1490nm transmitter and a 1310nm filter on the receiver and the Down side as a 1310nm transmitter and a 1490nm filter on the receiver.

Test Modules

DoS

Running a DoS attack against PON is super trivial. As long as one endpoint / ONT permanently fires its LED, the whole port on the OLT is dead, well at least the upstream. The clients on the line use time division multiplexing, or otherwise said, each ONT has it’s own time window in which it may speak as is otherwise silent. This way each ONT takes its turn to transmit data. Logically, if one ONT carrys on transmitting, it will interfere with the other ONT’s communication.

Abbreviations

Links

Projects

• VOLTHA (Virtual OLT Hardware Abstraction)
• Github: 0liv1er/omci-wireshark-dissector
• Github: fabiosvaz/omci-wireshark-dissect

Standards

• ONU Management and Configuration Interface, ITU Flyer
• G.988 : ONU management and control interface (OMCI) specification