3Com 3C13618 Command Reference Manual page 221

3Com Router Command Reference Guide — V1.00
SLIP simply defines the start and end signs for a frame so as to intercept the IP packet
on the serial line. As compared with PPP, it involves no address concept, no negotiation
process, no packet type discrimination (so only one network protocol can be supported
at one time), and no error correction function.
The link layer protocol of the interface shall be the same with that of the peer interface.
Example
# Configure the link layer protocol of interface Serial0 to SLIP.
[3Com-Serial0]link-protocol slip
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