Hi all,

I am logged in on mslync client 2010 with one account (A) on two PCs, and logged in with one account (B) on another PC. from B, I started chat conversation to A. on both ms lync clients which has A online there is a notification toast but I did not do  anything. About 15s latter, on one ms lync client the toast disappeared, on other one chat window with B appeared. I saw the log file of first ms lync client (the toast disappeared) had sip message:

SIP/2.0 486 Busy Here
Via: SIP/2.0/TLS 193.180.17.93:443;branch=z9hG4bK2743851D.9F55E1E083F72B47;branched=FALdf;ms-internal-info="asBwDa01sGgndwPtdOvhGL7pnRKEN-m0qFz-sZ_EdUAG3g4VWf1HnargAA"
Via: SIP/2.0/TLS 153.88.97.36:5061;branch=z9hG4bKDFF45307.F122F1A582CD1B48;branched=FALdf;received=153.88.97.219;ms-received-port=5061;ms-received-cid=51142C01
Via: SIP/2.0/TLS 153.88.97.33:50836;branch=z9hG4bK19E2C4B3.7E343B84F7522B47;branched=TRUE;ms-received-port=50836;ms-received-cid=12A7FA00
Via: SIP/2.0/TLS 153.88.97.30:58240;branch=z9hG4bK3A602237.967B985EA69D1B46;branched=FALdf;ms-received-port=58240;ms-received-cid=1A136000
Via: SIP/2.0/TLS 153.88.97.36:63326;branch=z9hG4bK29230502.21A5A16B82CD1B48;branched=FALdf;received=153.88.97.10;ms-received-port=63326;ms-received-cid=26AE3100
Via: SIP/2.0/TLS 153.88.251.215:53423;branch=z9hG4bK95D8D206.E81FDF5883F15B47;branched=FALdf;received=153.88.97.10;ms-received-port=53423;ms-received-cid=12ACBD00
Via: SIP/2.0/TLS 192.168.1.119:1130;received=193.180.17.72;ms-received-port=1130;ms-received-cid=51FF1200
From: "IabcvTestUdfrAD OADson"<sip:iabcvtestudfrad.oadson@xxxxxxx.com>;tag=3af7d9d245;epid=6073bab363
To: <sip:testudfrd.iabcvation@xxxxxxx.com>;epid=b69d5b2a83;tag=8eede4c250
Call-ID: 8b8147677dd142878b0a5533da2a2b0f
Cdfq: 1 INVITE
Record-Route: <sip:sip.xxxxxxx.com:443;transport=tls;opaque=state:Ci.R51fcbd00;lr;ms-route-sig=drHb3hg6yzc35A6sN2bLUXu0hYxWQFeVRRYFD8vBj9Tevg4VWf-YrkSAAA>;ms-rrsig=dr-fD-UHYF4fR4gxS1oakHRjxsGCjqGvMSAXIPco_24lLg4VWf-YrkSAAA;tag=8DA638E40D1279351D629FBB78A791FC
Record-Route: <sip:dirpool01.dbcas.xxxxxxx.df:5061;transport=tls;ms-fe=EdfSSMW1652.dbcas.xxxxxxx.df;lr;received=153.88.97.219;ms-received-cid=51142C01>;tag=987550853679A3E26A20014F7CF99B1B
Record-Route: <sip:fepool01.dbcas.xxxxxxx.df:5061;transport=tls;ms-fe=edfssmw1650.dbcas.xxxxxxx.df;opaque=state:F;lr>;tag=F35E1A4A9C8418D8CAC887D7435618E8
Record-Route: <sip:fepool01.dbcas.xxxxxxx.df:5061;transport=tls;ms-fe=edfssmw1647.dbcas.xxxxxxx.df;opaque=state:T;lr>;tag=358CF3A7B6D8B26576A99D01AFC6A88C
Udfr-Agent: UCCAPI/4.0.7577.4356 OC/4.0.7577.4356 (Microsoft Lync 2010)
Ms-client-diagnostics: 52067; reason="The ringing timer has expired and this location is not the callee's most active endpoint"
Supported: ms-conf-invite
Proxy-Authorization: TLS-DSK qop="auth", realm="SIP Communications dfrvice", opaque="5D646B3C", targetname="EdfSSMW1652.dbcas.xxxxxxx.df", crand="a39a8352", cnum="131", respondf="33a520c23aba9f1e599a4748c18d348017c4a30a"
Content-Length: 0

How ms lync client know whether it is the most active enpoint or not?

Thank you very much.

Hi, this forum is for Lync SDK development questions, so we will likely be unable to answer your question. Since you are asking about Lync client behavior, I will attempt to move your question to the appropriate Lync client forum on TechNet.

Lync Server determines which endpoint is currently most active for that user. For example, a user might be Away at two of the three endpoints, so the server sends the message only to the endpoint where the user is Available. If the server is unable to determine which state is most active, it sends the message to the endpoint it determines most likely active and waits to see if the user acknowledges the toast at any location. If the user opens the toast at an endpoint, the server removes the message from the other endpoints. If an endpoint doesnt acknowledge the message, the server leaves the message at only one location which is the most likely endpoint.