DynamicAccess Class of Service is only available with the 3C319 NIC NDIS 4 driver. This feature is not available with other 3C319 NIC drivers.This chapter describes enabling and configuring DynamicAccess Class of Service support for Windows 95 and Windows NT.
The DynamicAccess Class of Service feature lets you select critical applications for high-priority network access. Class of Service prioritization allows stations running critical applications under Windows 95 or Windows NT to access network bandwidth before other stations. The NDIS 4 driver requests a priority token when the selected applications transmit data.
DynamicAccess Class of Service is only available with the 3C319 NIC NDIS 4 driver. This feature is not available with other 3C319 NIC drivers.
The DynamicAccess Class of Service feature is disabled by default; if you want to take advantage of this feature, you must manually enable it after installing the NDIS 4 driver.
The 3C319 NIC must be installed and configured before you configure DynamicAccess Class of Service. For installation instructions, see , ." If your operating system does not automatically detect and configure the NIC, you must configure the NIC manually. See , ," for instructions.
The NDIS 4 driver must also be installed before you configure DynamicAccess Class of Service. For installation instructions, see , ," or see , ."
Finally, you must also have installed the appropriate applications that you want to prioritize.
To select Class of Service applications in a Windows 95 or Windows NT environment, follow these steps:
1 . In the Control Panel group, double-click the Class of Service icon.
Figure 7-1 3Com Class of Service Setup Screen
2 . Click Enable in the Class of Service box.
3 . Click the boxes next to the appropriate application names for which you want to activate Class of Service.
If an application is not listed here, you can obtain the necessary information from the application's manufacturer and manually enter the information in the Additional Ranges tab.
4 . Click OK.
You can add information for Class of Service applications that you want to prioritize but which are not listed on the 3Com Class of Service Setup screen ().
You must specify port or socket ranges as well as the network protocol being used. Obtain the information from the application manufacturer. The Class of Service network driver uses these ranges to determine whether a packet should be treated as high-priority.
To add the Class of Service ranges and protocols, follow these steps:
1 . Click the Additional Ranges tab.
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Figure 7-2 Initial Class of Service Additional Ranges Screen
2 . Enter the beginning of the port or socket range for the application in the Range Start box.
3 . Enter the inclusive range end value of the port or socket range for the application in the Range End box.
4 . Select the protocol that the application uses.
5 . Once the Range Start, Range End, and Protocol are entered press Add.
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Figure 7-3 Class of Service Additional Ranges Screen with Added Ranges
6 . Click OK when you are finished.
You can use Class of Service Advanced Options to adjust the network driver's handling of certain types of Class of Service traffic. In general, you do not need to change these values. Contact your network administrator before using these options.
To access the advanced options, follow these steps:
1 . To display the Class of Service Advanced Options screen, click the Advanced Options tab.
Figure 7-4 Class of Service Advanced Options Screen
2 . Enter new information as required.
3 . Click OK to set the new value.
4 . Reboot the system to activate changes.
This section provides a detailed description of each Advanced Values field shown on the Class of Service Advanced Options screen ().
The Advanced Options section of the Class of Service Advanced Options Screen shown in lower part of is not currently available for token ring installations.
This setting controls the number of non-Class of Service packets the network driver will allow in the FIFO ahead of any Class of Service packets. A smaller number decreases the time between Class of Service packets but can adversely affect performance. A value of 12 is recommended.
This option controls the number of simultaneous multimedia UDP packet streams the network driver can handle at any time. For many applications, the number of UDP streams is the same as the number of connections.
For example, for videoconferencing with three people, applications use three UDP streams for the video data. The value must be a power of two (2, 4, 8) but the optimal value may vary depending on the PC and application.
A video server may support 32 connections, but a client may only want to conference with four other people at a time.
A value of 16 is recommended for most applications.
When Class of Service support is enabled, high-priority packets are always transmitted before low-priority packets. If a certain high-priority application sends out enough packets, no low-priority packets may be sent.
To prevent this problem, the driver uses a ratio value to periodically send out a low-priority packet (if one is waiting to be sent).
For example, if a value of 1000 is entered, one low-priority packet would be sent for every 1000 high-priority packets. A value of 25 is recommended for most applications.
This field is not applicable for token ring installations. Any value entered in this field is ignored.
This option is not currently enabled for token ring installations. Any setting is ignored.
This option is not currently enabled for token ring installations. Any setting is ignored.
An alternative way to access DynamicAccess Class of Service is to click the Properties button with the 3C319 NIC selected while you are viewing the adapters list. Using this method also allows you to disable or enable the auto ring speed detection option.
The auto ring speed detection option permits the NDIS 4 driver for Windows 95 and Windows NT to detect and operate at the current ring data rate. Auto ring speed detection is automatically enabled when you load the NDIS 4 driver. (This feature is not available with other 3C319 NIC drivers.)
To manually set the ring speed after disabling auto ring speed detection, see " in .
The access paths for auto ring speed detection and DynamicAccess Class of Service through the Properties button are slightly different for Windows 95 and Windows NT. The following procedures describe the different paths.
To access the auto ring speed detection option in a Windows 95 environment, follow these steps:
1 . In the My Computer group, double-click the Control Panel icon.
2 . In the Control Panel group, double-click the System icon.
3 . In the System Properties dialog box, click the Device Manager tab.
4 . In the Device Manager tab, double-click Network adapters.
5 . Select 3Com TokenLink Velocity ISA (3C319) Adapter and click Properties.
Figure 7-5 3Com TokenLink Velocity ISA Adapter Dialog Box
To access the auto ring speed detection option and DynamicAccess Class of Service applications in a Windows NT environment, follow these steps:
1 . In the My Computer group, double-click the Control Panel icon.
2 . In the Control Panel group, double-click the Network icon.
3 . In the Network dialog box, click the Adapters tab.
4 . In the Adapters tab, select 3Com TokenLink Velocity ISA (3C319) Adapter and click Properties.
The 3Com TokenLink Velocity ISA (3C319) Adapter dialog box () lets you disable or enable auto ring speed detection.
Auto ring speed detection is automatically enabled when you load the NDIS 4 driver. When enabled, the Auto Ring Speed Detect option is checked. To disable the option follow these steps:
1 . In the 3Com TokenLink Velocity ISA (3C319) Adapter dialog box (), click the marked Auto Ring Speed Detect check box to clear it.
2 . Click OK.
The 3Com TokenLink Velocity ISA (3C319) Adapter dialog box () lets you manually set a locally administered address (LAA). In most cases, you use a preset NIC address and leave this field blank. Check with your network administrator before using this feature.
To set a locally administered address, follow these steps:
1 . With the 3Com TokenLink Velocity ISA (3C319) Adapter dialog box displayed (), type a valid 12-digit address in the Network Address (LAA) field.
2 . Click OK.
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