Configuring Your Gateway
Table 11. Wireless Advanced Settings Options Option Description
BG Protection Mode This mode is a protection mechanism that prevents collisions among 802.11b/g modes. Choices are:
Auto = BG protection mode goes on or off automatically as needed.
Always-On = BG protection mode is always on.
Always-Off = BG protection mode is always off. (default)
IGMP Snooping Enables or disables the Gateway from forwarding multicast traffic intelligently.
• Enable = Gateway listens to IGMP membership reports, queries, and leave messages to identify the
Gateway ports that are members of multicast groups. Multicast traffic will only be forwarded to ports
identified as members of the specific multicast group or groups..
• Disable = Gateway does not analyze all IGMP packets. (default)
WMM Configuration Displays a screen for selecting Wi-Fi Multimedia (WMM) settings for your wireless access point(s).
HT Physical Mode
Operating Mode Lets you select between Mixed Mode and Green Field.
Mixed Mode = provides backward compatibility with IEEE 802.11n/a/g/b devices. (default)
Green Field = used for pure network of 802.11n access points and clients, taking full advantage of the
high-throughput capabilities of the 11n MIMO architecture
Channel BandWidth Select a channel bandwidth of 20 or 20/40.
• 20 = allows only single-channel operation (e.g., 20 MHz).
• 20/40 = allows both single channel operation (20 MHz) and the wider bandwidth operation (40 MHz) by
using two or more adjacent (contiguous channels). A 20/40 BSS is a wireless network that allows a
wider bandwidth operation mode. (default)
Guard Interval The guard interval is the period in nanoseconds that the Gateway listens between packets. Choices are:
• Long = 800 ns guard interval.
• Short = 400 ns guard interval (default)
MCS Modulation Coding Scheme (MCS) is a specification of PHY parameters consisting of modulation order
(BPSK, QPSK, 16-QAM, 64-QAM) and FEC code rate (1/2, 2/3, 3/4, 5/6). MCS is used in your Gateway to
define 32 symmetrical settings. MCS provides for potentially greater throughput. High throughput data
rates are a function of MCS, bandwidth, and guard interval. Default is auto.
Reverse Direction Grant
(RDG) Speeds up data transmission between the Gateway and 802.11n access points and clients by allowing
wireless workstations to send/receive data simultaneously, without contending for shared medium. Default
is enable.
Extension Channel Defines a second 20-MHz channel. 40-MHz stations can use this channel in addition to using the control
channel simultaneously.
Aggregation
MSDU(A_MSDU) Enables or disables aggregation of multiple MSDUs in one MPDU. Default is disable.
Auto Block ACK Enables or disables Auto Block ACL function. Default is disable.
Decline BA Request Enables or disables the BA request function. Default is disable.
Other
HT TxStream Select 1 or 2 from the pull-down menu. Default is 2.
HT RxStream Select 1 or 2 from the pull-down men u. Default is 2.
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SMCD3GN Wireless Cable Modem Gateway User Manual