Introduce my Topology, we selected the Consolidated Edge Topology, followed it:

+ OCSEDGE01:

Internal NIC#1~10.1.1.145

External NIC#2~192.168.1.24

Ready set the Persistent Route for the Internal Interface.

+ OCSSER01:

OCS 2007 Enterprise

Internal NIC#1~10.1.1.200

+Remote User:

OC 2.0 6362, IP~201.1.1.1

I set the OCSEDGE01 well done, make the certificate exactly, but Remote User cannot logon OCS with Temporarily Unavailable.

Then I open the Logging Tools in the Edge server, I tracking the Log with Remote User Login, the logfile following it, and I will explaining it:

//First all , OCS Edge Server negotiate with Remote User's OC Client by TLS, The TEXT information is "TLS negotiation started". OCS Edge Server Use SIP TCP Port 5061 do it.

TL_INFO(TF_CONNECTION) [1]0BFC.12F8::04/29/2008-09:10:26.605.00028a11 (SIPStack,SIPAdminLog::TraceConnectionRecord:1224.idx(161))$$begin_record
LogType: connection
Severity: information
Text: TLS negotiation started
Local-IP: 192.168.1.24:5061
Peer-IP: 201.1.1.1:1149
Connection-ID: 0x400
Transport: TLS
$$end_record

//OC Client send a SIP pack to Edge Server, the pack head is a request information. like this.

TL_INFO(TF_PROTOCOL) [2]0BFC.0318::04/29/2008-09:10:27.542.00028acc (SIPStack,SIPAdminLog::TraceProtocolRecord:1224.idx(122))$$begin_record
Instance-Id: 00000005
Direction: incoming;source="external edge";destination="internal edge"
Peer: 201.1.1.1:1149
Message-Type: request
Start-Line: REGISTER sip:ehloex.com SIP/2.0
From: <sip:ocstest@ehloex.com>;tag=6a21753802;epid=280e54fbf0
To: <sip:ocstest@ehloex.com>
CSeq: 1 REGISTER
Call-ID: 3530cc364d594ad6945849d4208c0b2e
Via: SIP/2.0/TLS 201.1.1.1:1149
Max-Forwards: 70
Contact: <sip:201.1.1.1:1149;transport=tls;ms-opaque=d3470f2e1d>;methods="INVITE, MESSAGE, INFO, OPTIONS, BYE, CANCEL, NOTIFY, ACK, REFER, BENOTIFY";proxy=replace;+sip.instance="<urn:uuid:F328F58A-5EE3-5906-811C-EA976787A6E8>"
User-Agent: UCCP/2.0.6362.0 OC/2.0.6362.0 (Microsoft Office Communicator)
Supported: gruu-10, adhoclist, msrtc-event-categories
Supported: ms-forking
ms-keep-alive: UAC;hop-hop=yes
Event: registration
Content-Length: 0
Message-Body: �C
$$end_record

//After OC Client sending done, Edge Server will make it available by matching its configuration, then will take one entry by REGISTER.

TL_INFO(TF_DIAG) [2]0BFC.0318::04/29/2008-09:10:27.542.00028b22 (SIPStack,SIPAdminLog::TraceDiagRecord:1224.idx(144))$$begin_record
LogType: diagnostic
Severity: information
Text: The message has an internally supported domain
SIP-Start-Line: REGISTER sip:ehloex.com SIP/2.0
SIP-Call-ID: 3530cc364d594ad6945849d4208c0b2e
SIP-CSeq: 1 REGISTER
Peer: 201.1.1.1:1149
Data: domain="ehloex.com"
$$end_record

//So, Edge Server will try to resolve OCSSRV01 FQDN, the OCS Front-End server, If succeed, Will record this.

TL_INFO(TF_DIAG) [1]0BFC.12F8::04/29/2008-09:10:27.620.00028cd5 (SIPStack,SIPAdminLog::TraceDiagRecord:1224.idx(144))$$begin_record
LogType: DNS
Severity: information
Text: DNS query was successfully resolved
Query: pool01.ehloex.com
Query-Type: A
Query-Result: 10.1.1.200
TTL: 300
$$end_record

//But then, Edge server cannot establish connect with OCSSRV01, this is the CANCER, and will tell me the Result-Code is: 0x8007274c WSAETIMEDOUT.

TL_ERROR(TF_CONNECTION) [1]0BFC.12F8::04/29/2008-09:10:48.745.00029afb (SIPStack,SIPAdminLog::TraceConnectionRecord:1224.idx(157))$$begin_record
LogType: connection
Severity: error
Text: Failed to complete outbound connection
Peer-IP: 10.1.1.200:5061
Peer-FQDN: pool01.ehloex.com
Connection-ID: 0x502
Transport: TLS
Result-Code: 0x8007274c WSAETIMEDOUT
$$end_record

//Okay, timeout! Never keep walking with OCS front-end server, so the OCS will record a new entry with this.

TL_ERROR(TF_DIAG) [1]0BFC.12F8::04/29/2008-09:10:48.745.00029afe (SIPStack,SIPAdminLog::TraceDiagRecord:1224.idx(140))$$begin_record
LogType: diagnostic
Severity: error
Text: Message was not sent because the connection was closed
SIP-Start-Line: REGISTER sip:ehloex.com SIP/2.0
SIP-Call-ID: 3530cc364d594ad6945849d4208c0b2e
SIP-CSeq: 1 REGISTER
Peer: pool01.ehloex.com:5061
$$end_record

//So edge server will got a new record about TIME-OUT!

TL_INFO(TF_DIAG) [1]0BFC.12F8::04/29/2008-09:10:48.745.00029bc0 (SIPStack,SIPAdminLog::TraceDiagRecord:1224.idx(144))$$begin_record
LogType: diagnostic
Severity: information
Text: Response successfully routed
SIP-Start-Line: SIP/2.0 504 Server time-out
SIP-Call-ID: 3530cc364d594ad6945849d4208c0b2e
SIP-CSeq: 1 REGISTER
Peer: 201.1.1.1:1149
Data: destination="Unknown"
$$end_record

//The OCS edge server so friendly, she will send a new pack to the OC Client, its will tell the OC Client with "SIP/2.0 504 Server time-out", like said "Hei, Dude, I cannot find your MOM, sorry!"

TL_INFO(TF_PROTOCOL) [1]0BFC.12F8::04/29/2008-09:10:48.745.00029bc5 (SIPStack,SIPAdminLog::TraceProtocolRecord:1224.idx(122))$$begin_record
Instance-Id: 00000006
Direction: outgoing;source="local";destination="external edge"
Peer: 201.1.1.1:1149
Message-Type: response
Start-Line: SIP/2.0 504 Server time-out
From: <sip:ocstest@ehloex.com>;tag=6a21753802;epid=280e54fbf0
To: <sip:ocstest@ehloex.com>;tag=377BC973C488486BA0FB4DF1F8D094A3
CSeq: 1 REGISTER
Call-ID: 3530cc364d594ad6945849d4208c0b2e
ms-user-logon-data: RemoteUser
Via: SIP/2.0/TLS 201.1.1.1:1149;ms-received-port=1149;ms-received-cid=400
Content-Length: 0
Message-Body: �C
$$end_record

TL_WARN(TF_DIAG) [1]0BFC.12F8::04/29/2008-09:10:48.745.00029bed (SIPStack,SIPAdminLog::TraceDiagRecord:1224.idx(142))$$begin_record
LogType: diagnostic
Severity: warning
Text: Routing error occurred; check Result-Code field for more information
Result-Code: 0x80004004 E_ABORT
SIP-Start-Line: REGISTER sip:ehloex.com SIP/2.0
SIP-Call-ID: 3530cc364d594ad6945849d4208c0b2e
SIP-CSeq: 1 REGISTER
Peer: pool01.ehloex.com:5061
$$end_record

TL_INFO(TF_CONNECTION) [2]0BFC.1134::04/29/2008-09:10:48.949.00029c12 (SIPStack,SIPAdminLog::TraceConnectionRecord:1224.idx(161))$$begin_record
LogType: connection
Severity: information
Text: TLS connection closed
Local-IP: 192.168.1.24:5061
Peer-IP: 201.1.1.1:1149
Connection-ID: 0x400
Transport: TLS
$$end_record

TL_INFO(TF_PROTOCOL) [2]16F8.04EC::04/29/2008-09:10:51.089.00029e2e (S4,SipMessage.DataLoggingHelper:472.idx(550))
<<<<<<<<<<<<Incoming SipMessage c=[<SipTlsConnection_43B3FA>], 10.1.1.145:5062<-10.1.1.200:4803
SERVICE sip:UAP-ST-TWEB01.st.gd.uap:5062;grid SIP/2.0
FROM: "....."

OK, I found it! The Result-Code "0x8007274c WSAETIMEDOUT"!! But what is mean that? And the code 0x8007274c MEAN WHAT?

Try my hard, I found the code means, like that: "0x8007274C ->  (System) A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. "

Thanks God, I found the reason with this error, the route error. So I check my Firewall's configuration, and I found the route by OCS EDGE SERVER with OCS FRONT-END SERVER has some trouble, then I fix it, it is work so successful!