> For the complete documentation index, see [llms.txt](https://prosbcdocs.telcobridges.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines.md).

# Transmission and lines

- [TDM](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/tdm.md)
- [Automatic Protection Switching](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/automatic-protection-switching.md)
- [Channelize STM-1 to E1 Channel Mapping](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/channelize-stm-1-to-e1-channel-mapping.md)
- [DS3 Interfaces](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/ds3-interfaces.md)
- [HDLC](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/hdlc.md): High-Level Data Link Control (HDLC): the framing protocol that encapsulates SS7 and other traffic, and why a full-duplex SS7 link needs two controllers.
- [KLM vs ITU-T vs Alcatel](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/klm-vs-itu-t-vs-alcatel.md)
- [Line Interface](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/line-interface.md)
- [Line Service](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/line-service.md)
- [PCM](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/pcm.md): Pulse code modulation (PCM): the digital encoding of analogue audio that is the native voice format on wireline and mobile TDM networks.
- [Performance metrics](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/performance-metrics.md)
- [SONET/SDH interfaces](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/sonet-sdh-interfaces.md): SONET and SDH line interfaces on Tmedia: how an OC3 or STM-1 optical interface is configured to carry the line services beneath it.
- [STM-1](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/stm-1.md): STM-1, also known as SDH or OC-3: the 155 Mbit/s optical multiplexing standard, and how TelcoBridges gateways terminate and channelise it.
- [T1, E1, and J1 interfaces](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/t1-e1-and-j1-interfaces.md)
- [T1/E1/J1 RJ48 Cable Diagram](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/t1-e1-j1-rj48-cable-diagram.md): RJ48 pinout for building your own T1, E1 or J1 cables for Tmedia and Tdev products with modular 8-conductor jacks.
- [Timeslot](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/timeslot.md)
- [TMS Network Synchronization](https://prosbcdocs.telcobridges.com/telecom-references/transmission-and-lines/tms-network-synchronization.md)


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