Incoming Call Support With Distributed Link Services

• Microsoft SNA Server for Windows NT, version 2.11 Service Pack 1

SYMPTOMS

After you install SNA Server 2.11 Service Pack 1, the new 802.2 Distributed Link Service feature does not support incoming calls.

CAUSE

If Distributed Link Service is set up to allow more than one SNA Server to use the same Distributed Link Service, the link service does not know which server to send the incoming XID. The chosen server may reject the connection unless it is set up for incoming calls.

STATUS

Microsoft has confirmed this to be a problem in SNA Server version 2.11 Service Pack 1. This problem was corrected in the latest Microsoft SNA Server 2.11 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

An enhancement has been made for 802.2 Distributed Link Services. Some WAN implementations benefit from decreased traffic on the network.

For example, an SNA Server uses an 802.2 Distributed Link Service to connect to a Cluster Controller over Token Ring. The network is physically separated into two segments, connected by an X.25 network. The SNA Server that distributes the link is on the same segment as the Cluster Controller. The SNA Server running the Distributed Link Service is located on the other segment.

Since the X.25 line is billed by usage, it is necessary to limit the amount of traffic in the WAN. Instead of keeping the connection Active continuously, allowing the 802.2 Distributed Link Service to accept incoming calls represents substantial savings due to the fact that the connection remains inactive until needed.

NOTE: The SNA Server Link Service used is DLC 802.2 over Token Ring. The WAN link uses the Packet Switched Network. If the connection is established to use an X.25 Link Service, the above case does not apply.