User`s guide

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This option causes the interface to become activated but rather than using the idle timer
associated with the interface, specify the idle timeout.
Inhibit other PPP interface if this PPP interface is disconnected but operational
When checked, this checkbox enables this PPP instance to inhibit other PPP instances if it is
operational but not currently active.
Attempt to negotiate DEFLATE compression on this interface
When checked, this checkbox causes the router to compress the data transferred over this
link. When unchecked, compression is disabled. The effectiveness of data compression will
vary with the type of data but a typical ratio achieved for a mix of data such as web pages,
spreadsheets, databases, text files and (uncompressed) image files would be between 2:1
and 3:1. Using compression has the effect of increasing the effective throughput. Using
compression may offer cost savings on a network where charges are based upon the
amount of data transferred (e.g. W-WAN networks). If the data is already compressed (e.g.
.zip files or JPEG images) then the compression algorithm will detect this and send the data
without attempting further compression.
Attempt to negotiate MPPE encryption on this interface
When checked, this checkbox causes the router to attempt to negotiate Microsoft Point-to-
Point Encryption (MPPE) with the remote peer. If the remote peer is unable to negotiate
MPPE, negotiations will fail. When negotiated, the PPP instance will encrypt the PPP frames
as per the MPPE specification.
MPPE key size
The values in this drop-down list select the length (in bits) of the encryption key. The
options are:
• Auto
• 40 bits
• 56 bits
• 128 bits.
“Auto” indicates that the router will accept whatever the remote suggests. For the other
values, the remote must accept and request the key size specified, else the PPP
negotiations will fail.
Enable MPPE stateless mode
When this checkbox is checked, the router will negotiate stateless mode in which the
session key is changed after the transmission of each packet. Stateless mode may be
useful for lossy links.
Note:
MPPE does not provide authentication, only encryption. This is because the encryption keys
are determined by the PPP engines themselves on start-up.
TCP transmit buffer size n bytes
When the value in this text box is set to a non-zero value, the router will use the value to
set the size of the TCP buffer for transmitted packets. This is useful for slow and/or lossy
connections such as satellite links. Setting this buffer to a low value will prevent the amount
of unacknowledged data from getting too high. If retransmits are required, a smaller TX
buffer helps prevent retransmits flooding the connection.
Related CLI Commands
Entity
Instance
Parameter
Values
Equivalent Web Parameter
ppp n metric 0 - 255 Metric