User guide

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dynamic DNS. Allows you to use the free services of www.dyndns.org.

Dynamic DNS automatically directs any public Internet request for your com-

puter's name to your current dynamically-assigned IP address.

-----E-----

echo interval. Frequency with which the router sends out echo requests.

Enable. This toggle button is used to enable/disable the conﬁgured tunnel.

encapsulation. Technique used to enclose information formatted for one

protocol, such as AppleTalk, within a packet formatted for a different proto-

col, such as TCP/IP.

Encrypt Protocol. Encryption protocol for the tunnel session.

Parameter values supported include NONE or ESP.

encryption. The application of a speciﬁc algorithm to a data set so that any-

one without the encryption key cannot understand the information.

ESP. Encapsulation Security Payload (ESP) header provides conﬁdentiality,

data origin authentication, connectionless integrity, anti-replay protection,

and limited trafﬁc ﬂow conﬁdentiality. It encrypts the contents of the data-

gram as speciﬁed by the Security Association. The ESP transformations

encrypt and decrypt portions of datagrams, wrapping or unwrapping the dat-

agram within another IP datagram. Optionally, ESP transformations may per-

form data integrity validation and compute an Integrity Check Value for the

datagram being sent. The complete IP datagram is enclosed within the ESP

payload.

Ethernet crossover cable. See crossover cable.

-----F-----

FCS. Frame Check Sequence. Data included in frames for error control.

ﬂow control. Technique using hardware circuits or control characters to reg-

ulate the transmission of data between a computer (or other DTE) and a

modem (or other DCE). Typically, the modem has buffers to hold data; if the