Cisco DPC3827 User Manual page 43

Section
Status
4025083 Rev A
Field Description

Manual
– Encryption: The Encryption method determines the length of
the key used to encrypt/decrypt ESP packets. Note that both
sides must use the same method.
– Encryption Key: This field specifies a key used to encrypt
and decrypt IP traffic. Both character and hexadecimal values
are acceptable in this field. Note that both sides must use the
same Encryption Key.
– Authentication: The Authentication method authenticates
the Encapsulating Security Payload (ESP) packets. Select
MD5 or SHA. Note that both sides (VPN endpoints) must
use the same method.
 MD5: A one-way hashing algorithm that produces a
128-bit digest
SHA: A one-way hashing algorithm that produces a

160-bit digest
– Authentication Key: This field specifies a key used to
authenticate IP traffic. Both character and hexadecimal
values are acceptable in this field. Note that both sides must
use the same Authentication Key.
– Inbound SPI/Outbound SPI: The Security Parameter Index
(SPI) is carried in the ESP header. This enables the receiver to
select the SA, under which a packet should be processed. The
SPI is a 32-bit value. Both decimal and hexadecimal values
are acceptable, e.g., "987654321" or "0x3ade68b1". Each tunnel
must have a unique Inbound SPI and Outbound SPI. No two
tunnels share the same SPI. Note that the Inbound SPI must
match the remote gateway's Outbound SPI, and vice versa.
This field shows the connection status for the selected tunnel. The
state is either Connected or Disconnected.
How Do I Configure My DOCSIS Residential Gateway?
43