Nokia M5122 User Manual
E
Copyright Nokia Networks Oy
C33874002SE_A0
20
maximum transmit rate on the VCC is equal to the ADSL upstream
capability.
The ADSL transmission is based on the DMT line code. M5122
provides a DMT line rate up to 8 Mbit/s downstream and up to 800
kbit/s upstream. The DMT transceiver is rate adaptive and capable of
providing faster rates over short distances or slower rates over long
distances. The transceiver adapts itself to the line conditions and rate
adaptation is done in steps of 32 kbit/s. The network operator can set
the data rates as a part of the network management functionality
provided by Nokia DSLAM.
M5122 supports ATM over ADSL transmission ITU-T G.992.1 and
ADSL Lite ITU-T G.992.2. The ADSL mode can be changed through
the command line interface.
4.3
Dynamic Host Configuration Protocol
Note
Use DHCP with PPTP tunneling only.
M5122 can act as a Dynamic Host Configuration Protocol (DHCP)
server for the PCs on the end-user home network. In this mode, M5122
can assign up to 253+253 consecutive addresses from two separate
address ranges (that is, 253 consecutive addresses per address range)
to the PCs on the home network. Two separate address ranges can be
used if more than 253 addresses are required on the local subnet, if two
non-contiguous address ranges are needed or if an additional router
with DHCP relay is used on the local network. M5122 can also act as a
DHCP relay agent and relay the DHCP requests to an external DHCP
server.
4.4
Point-to-Point Tunneling Protocol (PPTP)
When PPTP local tunneling is used, a local network client initialises a
PPTP-tunneled PPP connection (VPN) to Nokia M5122. The modem
terminates the tunnel and all data from that terminated local PPTP
tunnel will be forwarded to an assigned ATM VCC by using PPP over
AAL5 encapsulation. Thus, each local PPTP tunnel requires an
equivalent ATM VCC assigned to it restricting the total number of
local PPTP hosts to 8.
