====== xDSL ======

{{:docs:xdsl.png|:docs:xdsl.png}}

===== Glossary =====

| PPPoE | PPP over Ethernet | RFC 2516 |
| PPPoA | PPP over ATM | RFC 2364 (PPP over AAL5) |
| L2TP | Layer 2 Tunneling Protocol | RFC 2661 |
| LAC | L2TP Access Concentrator ||
| LNS | L2TP Network Server ||

==== PPPoE ==== 

| PADT | PPPoE Active Discovery Terminate |
| PADI | PPPoE Active Discovery Initiation |
| PADO | PPPoE Active Discovery Offer |
| PADS | PPPoE Active Discovery Session-confirmation |
| PADR | PPPoE Active Discovery Request |

==== About ADSL time transmissions ====

These values are extract from Thomson SpeedTouch's manual (release 5.3.0)

^ Line Speed ^  MTU  ^^^^^^
| |  64  |  128  |  256  |  512  |  1024  |  1500  |
|  56 kb/s  |  9ms  |  18ms  |  36ms  |  72ms  |  144ms  |  214ms  |
|  64 kb/s  |  8ms  |  16ms  |  32ms  |  64ms  |  128ms  |  187ms  |
|  128 kb/s  |  4ms  |  8ms  |  16ms  |  32ms  |  64ms  |  93ms  |
|  256 kb/s  |  2ms  |  4ms  |  8ms  |  16ms  |  32ms  | 48ms  |
|  512 kb/s  |  1ms  |  2ms  |  4ms  |  8ms  |  16ms  |  23ms  |
|  1 Mb/s  |  0,640ms  |  1,2ms  |  2,6ms  |  5ms  |  10ms  |  15ms |