4 Protocol Examples

A client broadcasts a TopologyClientRequest packet and receives zero or more TopologyServerReply packets.

In a trivial example, the only response is from the current site server. In this case, the value in the DirectoryServiceServerCount field of the TopologyServerReply contains a zero value.

In a more typical example, there are two or more responses: one from the Primary Site Controller (PSC) of the site to which the client belongs and one or more responses from other PSCs.

The following sequence diagram shows a typical example.

Typical protocol example

Figure 1: Typical protocol example

Examples of the content of a TopologyClientRequest and two TopologyServerReply responses sent over TCP/IP are presented as follows.

The TopologyClientRequest data packet has the following content.

 Offset        Hexadecimal data value
 in packet
  
 00000000      00 01 00 00 61 BA EA E6 C6 D1 DB 11 BA AC 00 03 
 00000010      FF 4E 2D 22 03 A1 91 F2 3C E3 4F AB A9 30 BE 3A 
 00000020      33 E4 32 DD F6 1B C5 DC AD D4 43 45 87 39 71 56 
 00000030      8E 8F 91 28
  

The first TopologyServerReply data packet is from the local site server and does not contain a list of MSMQ Directory Service servers. The packet has the following content.

  
 Offset        Hexadecimal data value
 in packet
  
 00000000      00 02 00 00 03 A1 91 F2 3C E3 4F AB A9 30 BE 3A 
 00000010      33 E4 32 DD 01 00 00 00 00 00 00 00 00 00 00 00 
 00000020      62 BA EA E6 C6 D1 DB 11 BA AC 00 03 FF 4E 2D 22
  

The second TopologyServerReply data packet is from a site server of which the client is not a member and thus contains a list of MSMQ Directory Service servers; this packet is ignored because the requestor has received a reply from a server in the site of which the requestor is a member. The packet has the following content.

  
 Offset        Hexadecimal data value
 in packet
  
 00000000      00 02 00 00 03 A1 91 F2 3C E3 4F AB A9 30 BE 3A 
 00000010      33 E4 32 DD 01 00 00 00 00 00 00 00 12 00 00 00 
 00000020      62 BA EA E6 C6 D1 DB 11 BA AC 00 03 FF 4E 2D 22 
 00000030      60 BA EA E6 C6 D1 DB 11 BA AC 00 03 FF 4E 2D 22 
 00000040      31 00 30 00 6E 00 74 00 34 00 70 00 65 00 63 00 
 00000050      00 00
  
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