Note: Devices with built-in ADSL/SDSL modem resp. with an ISDN adapter make
these settings independently for the respective interface. For a LANCOM
model with Ethernet and ISDN interface, these settings have to
be made solely for the Ethernet interface.
- An Ethernet WAN (DSL/cable) interface can be switched off completely in this dialogue.
- As upstream and downstream rate the gross data rates are entered, which are usually a little bit higher than the net data rates indicated by the provider as the guaranteed data rate (see also ).
- The “external overhead” considers information added to the packets during the data transfer. Concerning applications with small data packets (e.g. Voice over IP), this extra overhead is quite noticeable. Examples for the external overhead:
| Transfer | External overhead | Note |
|---|---|---|
| PPPoEoA | 36 bytes | additional headers, loss by not completely used ATM cells |
| PPTP | 24 bytes | additional headers, loss by not completely used ATM cells |
| IPoA (LLC) | 22 bytes | additional headers, loss by not completely used ATM cells |
| IPoA (VC-MUX) | 18 bytes | additional headers, loss by not completely used ATM cells |
| Cable modem | 0 | direct transfer of Ethernet packets |
LANconfig: Interfaces / WAN
WEBconfig: Setup / Interfaces / DSL Interfaces
Note: Only upstream and downstream rates are indicated by Kbps, external
overhead in bytes/packet.