This information was created on Dec. 23rd, 2004 and applies to the following products and software versions:
Tsunami MP.11 Model 5054-RTsunami MP.11a
Tsunami MP.11
Tsunami QB .11
Software versions 2.1.0 and higher
Issue
The WORP protocol used by the Tsunami MP.11 products, utilizes polling to indicate which Residential Subscriber Unit (RSU) and Subscriber Unit (SU) is allowed to send traffic to the Base Station Unit (BSU). An SU is moved to "Sleep Mode" by the BSU when there is very little traffic over a period of time. When in "Sleep Mode", the SU is not polled as often by the BSU.
This "Sleep Mode" optimizes throughput, because little time is spent on needless polling of minimal active RSUs or SUs, but sometimes response time is negatively effected.
Feature
The v2.1.0 has a new feature, called "NoSleep". When enabled, the BSU will not move the SUs into "Sleep Mode". In this state, an SU is constantly being polled by a BSU and response times are improved. In a multipoint network, "NoSleep" negatively effects throughput. In large multipoint setups this affect can be detrimental.
NOTE: Please check the Recommendation section before enabling this feature.
This feature can be enabled by setting the rigth MIB variable through SNMP:
iso(1).org(3).dod(6).internet(1).private(4).enterprises(1).agere(11898).orinoco(2).orinocoObjects(1).orinocoIf(2).orinocoWORPIf(5).oriWORPIfConfigTable(1).oriWORPIfConfigTableEntry(1).oriWORPIfConfigTableNoSleepMode(7)
or in short:
1.3.6.1.4.1.11898.2.1.2.5.1.1.7 (oriWORPIfConfigTableNoSleepMode)
Values can be "1" (disable) or "2"(enable). By default, "NoSleep" is disabled on a Tsunami .11 BSU.
Since this feature can effect the overall throughput of the system, the configuration of this feature is allowed only via the SNMP interface and cannot be toggled by CLI or HTTP..
Recommendation
Enabling "NoSleep" mode has a definite impact on performance. The function is implemented to ensure proper performance in both small and large networks. When "NoSleep" is enabled, the SUs will be polled continuously, regardless of the amount of traffic, and this will consume bandwidth. The higher the number of SUs, the more bandwidth will be consumed.
For example, if there there are five SUs connected to the BSU and only one SU has traffic to send, then the BSU would need to send four empty polls to those SUs and receive four times a response from those four SUs between each two data exchanges with that one SU. This "NoSleep" feature could theoretically occupy up to 80% of the total bandwidth for a five SU network; therefore, extreme caution should be taken when enabling this feature.
It is recommended to disable "NoSleep" under any of the following conditions:
When the throughput of the network is lower then expected
When response times are increasing
When traffic is being dropped because of aged traffic
The "NoSleep" mode might be considered in the following situations:
When only one SU will be connected to the BSU, which means that the Tsunami operates in a Point to Point configuration
When varying response times are not acceptable. The response times may still vary, but the effect may be less with "NoSleep" enabled
When the potential number of SUs connecting to the BSU are relatively small
When the degradation of bandwidth availiblity is not an issue
No IEEE 802.11a device are using the same spectrum in any proximity
When "NoSleep" is enabled, it is recommended to do live tests with the desired application to confirm that this feature is compatible with the network and the applications runnning on that network.
Appendix
This "orinoco.mib" file is delivered with the product and can downloaded from the Proxim website along with the Tsunami application. The following is copy of this MIB:
oriWORPIfConfigTableNoSleepMode OBJECT-TYPE
SYNTAX ObjStatus
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object is used to enable or disable sleep mode. If this object
is enabled, a subscriber unit will not go into sleep mode when
they have no data to send."
DEFVAL { disable }
::= { oriWORPIfConfigTableEntry 7