SyncML protocol in WP8- client stops responding

Question

I'm trying to get my Windows Phone 8 MDM system to work. Currently device enrolls and makes initial SyncML request correctly. It also responds to queries in server's intitial response, but I assume that it doesn't like something in it. Reason being that it uses the retry intervals to make additional connections to server and then afterward doesn't connect anymore.

When I initiate the connection manually then it works, but automatic connections are not taking place. Strange thing is that internally the SyncML SessionID counter gets increased at specified intervals, but device doesn't even attempt to connect the server.

Here is my SyncML protocol

Client starts:

   <SyncML xmlns="SYNCML:SYNCML1.2">
  <SyncHdr>
    <VerDTD>1.2</VerDTD>
    <VerProto>DM/1.2</VerProto>
    <SessionID>E</SessionID>
    <MsgID>1</MsgID>
    <Target>
      <LocURI>https://ssl.../enrollment/omadmservice.php</LocURI>
    </Target>
    <Source>
      <LocURI>IMEI:35...64</LocURI>
      <LocName>riho</LocName>
    </Source>
    <Cred>
      <Meta>
        <Format xmlns="syncml:metinf">b64</Format>
        <Type xmlns="syncml:metinf">syncml:auth-md5</Type>
      </Meta>
      <Data>SoFh6khg4awLYXn2PQOOwQ==</Data>
    </Cred>
  </SyncHdr>
  <SyncBody>
    <Alert>
      <CmdID>2</CmdID>
      <Data>1201</Data>
    </Alert>
    <Replace>
      <CmdID>3</CmdID>
      <Item>
        <Source>
          <LocURI>./DevInfo/DevId</LocURI>
        </Source>
        <Data>IMEI:35...64</Data>
      </Item>
       ...
    </Replace>
    <Final/>
  </SyncBody>
</SyncML>

Server responds:

<SyncML xmlns="SYNCML:SYNCML1.2">
    <SyncHdr>
        <VerDTD>1.2</VerDTD>
        <VerProto>DM/1.2</VerProto>
        <SessionID>E</SessionID>
        <MsgID>1</MsgID>
        <Target>
            <LocURI>IMEI:35...64</LocURI>
        </Target>
        <Source>
            <LocURI>https://ssl.../enrollment/omadmservice.php</LocURI>
            <LocName>MDMServer</LocName>
        </Source>
        <Cred>
          <Meta>
            <Format xmlns="syncml:metinf">b64</Format>
            <Type xmlns="syncml:metinf">syncml:auth-md5</Type>
          </Meta>
          <Data>ryJ+boSmdCoO8BzxXcYSxg==</Data>
       </Cred>
    </SyncHdr>
    <SyncBody>
      <Status>
        <CmdID>1</CmdID>
        <MsgRef>1</MsgRef>
        <CmdRef>0</CmdRef>
        <Cmd>SyncHdr</Cmd>
        <Data>212</Data> 
      </Status>
    <Status>
        <MsgRef>1</MsgRef>
        <CmdRef>2</CmdRef>
        <CmdID>2</CmdID>
        <Cmd>Alert</Cmd>
        <Data>200</Data>
    </Status>
    <Status>
        <CmdID>3</CmdID>
        <MsgRef>1</MsgRef>
        <CmdRef>3</CmdRef>
        <Cmd>Replace</Cmd>
        <Data>200</Data>
    </Status>
    <Get>
        <CmdID>4</CmdID>
        <Item>
            <Target>
                <LocURI>./Vendor/MSFT/Registry/HKLM/Software/Microsoft/DeviceEncryption/Enabled</LocURI>
            </Target>
        </Item>
    </Get>
    </SyncBody>
</SyncML>

Client sends its response:

<SyncML xmlns="SYNCML:SYNCML1.2">
  <SyncHdr>
    <VerDTD>1.2</VerDTD>
    <VerProto>DM/1.2</VerProto>
    <SessionID>E</SessionID>
    <MsgID>2</MsgID>
    <Target>
      <LocURI>https://ssl.../enrollment/omadmservice.php</LocURI>
    </Target>
    <Source>
      <LocURI>IMEI:35...64</LocURI>
    </Source>
  </SyncHdr>
  <SyncBody>
    <Status>
      <CmdID>1</CmdID>
      <MsgRef>1</MsgRef>
      <CmdRef>0</CmdRef>
      <Cmd>SyncHdr</Cmd>
      <Chal>
        <Meta>
          <Format xmlns="syncml:metinf">b64</Format>
          <Type xmlns="syncml:metinf">syncml:auth-md5</Type>
          <NextNonce xmlns="syncml:metinf">kjjz6FyCYuYm9VUsSaHfKmj98GGfh9yeLvv8hlMNZak=</NextNonce>
        </Meta>
      </Chal>
      <Data>212</Data>
    </Status>
    <Status>
      <CmdID>2</CmdID>
      <MsgRef>1</MsgRef>
      <CmdRef>4</CmdRef>
      <Cmd>Get</Cmd>
      <Data>200</Data>
    </Status>
    <Results>
      <CmdID>3</CmdID>
      <MsgRef>1</MsgRef>
      <CmdRef>4</CmdRef>
      <Item>
        <Source>
          <LocURI>./Vendor/MSFT/Registry/HKLM/Software/Microsoft/DeviceEncryption/Enabled</LocURI>
        </Source>
        <Meta>
          <Format xmlns="syncml:metinf">int</Format>
        </Meta>
        <Data>1</Data>
      </Item>
    </Results>
    <Final/>
  </SyncBody>
</SyncML>

And server stores the data and drops connection.

Can anyone find a bug in my implementation? What more does client expect from server?

Answer 1

As I found out the problem was not in my implementation, but in buggy Microsoft documentation. In their "WP8 Enterprise Management Protocol 1.2" they fixed several typos and mistakes in their protocol and now connections work as supposed.