Blog

January 22, 2018
|

Skype for Business Web app debugging

When users are trying to join a ‘Skype for Business’ audio/video Conference call, they might get the following error

sfb-app1

To debug, do the following

  • Enable full logging by adding &log=full to the meeting url – https://meet.antuit.com/test.b/VA6P4QJ7?sl=1&log=full 
  • Web app logs are stored at %AppData%\Local\Microsoft\SkypeForBusinessPlugin\Tracing
  • ‘Candidate’ details are stored in JavaScript_yyyy-mm-dd_hh_mm_ss.log. Here is the Request
    <\request>, Lync_Client_Model_Transport_TransportUtils$$Q
    17:16:36:673, TL_INFO, , UCWASpecificCommunication,
    %!PII!v=0
    o=- 0 0 IN IP4 192.168.2.184
    s=session
    c=IN IP4 192.168.2.184
    b=CT:99980
    t=0 0
    m=audio 9178 RTP/AVP 117 104 114 9 112 111 0 103 8 116 115 97 13 118 101
    a=x-ssrc-range:617659136-617659136 a=rtcp-fb:* x-message app send:dsh recv:dsh
    a=rtcp-rsize
    a=label:main-audio
    a=x-source:main-audio
    a=ice-ufrag:ZYZo
    a=ice-pwd:Y/pkuAleAcNJipBBTRJwP81k
    a=candidate:1 1 UDP 2130706431 192.168.2.184 9178 typ host
    a=candidate:1 2 UDP 2130705918 192.168.2.184 9179 typ host
    a=x-candidate-ipv6:2 1 UDP 33553919 2001:0:9d38:953c:30d1:3e90:27f6:f8ec 10380 typ host
    a=x-candidate-ipv6:2 2 UDP 33553406 2001:0:9d38:953c:30d1:3e90:27f6:f8ec 10381 typ host
    a=candidate:3 1 TCP-ACT 1684798463 192.168.2.184 9178 typ srflx raddr 192.168.2.184 rport 9178
    a=candidate:3 2 TCP-ACT 1684797950 192.168.2.184 9178 typ srflx raddr 192.168.2.184 rport 9178
    a=cryptoscale:1 client AES_CM_128_HMAC_SHA1_80 inline:BqUjkcJUcCdV8RJb9yl8Ujprd/AV8KsWDkniMasW|2^31|1:1
    a=crypto:2 AES_CM_128_HMAC_SHA1_80 inline:qQb7c0CJePgLQEtQnyGUnoVS17iG3DFTm1Z5zx9R|2^31|1:1
    a=crypto:3 AES_CM_128_HMAC_SHA1_80 inline:Vv72zegbt/kwDFWXulYbxp6gc9XUeriliDSjJtNR|2^31
    a=maxptime:200
    a=rtcp:9179
    a=rtpmap:117 G722/8000/2
    a=rtpmap:104 SILK/16000
    a=fmtp:104 useinbandfec=1; usedtx=0
    a=rtpmap:114 x-msrta/16000
    a=fmtp:114 bitrate=29000
    a=rtpmap:9 G722/8000
    a=rtpmap:112 G7221/16000
    a=fmtp:112 bitrate=24000
    a=rtpmap:111 SIREN/16000
    a=fmtp:111 bitrate=16000
    a=rtpmap:0 PCMU/8000
    a=rtpmap:103 SILK/8000
    a=fmtp:103 useinbandfec=1; usedtx=0
    a=rtpmap:8 PCMA/8000
    a=rtpmap:116 AAL2-G726-32/8000
    a=rtpmap:115 x-msrta/8000
    a=fmtp:115 bitrate=11800
    a=rtpmap:97 RED/8000
    a=rtpmap:13 CN/8000
    a=rtpmap:118 CN/16000
    a=rtpmap:101 telephone-event/8000
    a=fmtp:101 0-16
    a=rtcp-mux
    a=ptime:20 !
    <\request>
  • Here is the Response
    <\response>, Lync_Client_Model_Transport_TransportUtils$$Q
    17:16:37:395, TL_INFO, , UCWASpecificCommunication,
    %!PII!v=0
    o=- 2 0 IN IP4 10.100.0.101
    s=session
    c=IN IP4 10.100.0.101
    b=CT:1000000
    t=0 0
    m=audio 51464 RTP/SAVP 117 9 111 0 8 97 13 118 101
    c=IN IP4 10.100.0.101
    a=rtcp-rsize
    a=rtcp-fb:* x-message app send:dsh recv:dsh
    a=x-ssrc-range:1001-1001
    a=x-source-streamid:2
    a=rtcp:51464
    a=ice-ufrag:7x5T
    a=ice-pwd:XTMdsnottY+c2/InbJdxf4/z
    a=rtcp-mux
    a=candidate:1 1 UDP 2130706431 10.100.0.101 51464 typ host
    a=candidate:2 1 tcp-pass 174456319 208.115.111.236 52437 typ relay raddr 10.100.0.101 rport 56637
    a=candidate:3 1 UDP 184548351 208.115.111.236 54051 typ relay raddr 10.100.0.101 rport 55834
    a=candidate:4 1 tcp-act 174848511 208.115.111.236 52437 typ relay raddr 10.100.0.101 rport 56637
    a=candidate:5 1 tcp-act 1684797439 10.100.0.101 56637 typ srflx raddr 10.100.0.101 rport 56637
    a=label:main-audio
    a=cryptoscale:1 server AES_CM_128_HMAC_SHA1_80 inline:ZKgQV9KMccdJq04ktJEXL2BRz4R8M3zCvDUu/CcL|2^31|1:1
    a=x-audioflow:sendonly
    a=x-dtmfflow:recvonly
    a=rtpmap:117 g722/8000/2
    a=fmtp:117 bitrate=128000
    a=rtpmap:9 g722/8000
    a=rtpmap:111 SIREN/16000
    a=fmtp:111 bitrate=16000
    a=rtpmap:0 PCMU/8000
    a=rtpmap:8 PCMA/8000
    a=rtpmap:97 RED/8000
    a=rtpmap:13 CN/8000
    a=rtpmap:118 CN/16000
    a=rtpmap:101 telephone-event/8000
    a=ptime:20 !
    <\response>,
  • MRAS in JavaScript_yyyy-mm-dd_hh_mm_ss.log
    17:16:20:885, TL_INFO, , MediaPlatformConfig, Media settings url
    /ucwa/v1/applications/11800687807/mediaPolicies, MRAS url
    /ucwa/v1/applications/11800687807/communication/mediaRelayAccessToken,
    Lync_Client_Model_Conversation_MediaPlatformConfig$start
    17:16:20:885, TL_INFO, , UCWASpecificCommunication, UCWA Communication desired
    -/ucwa/v1/applications/11800687807/mediaPolicies,
    Lync_Client_Model_Session_UCWACommunicator$send
  • ICE in PluginHost_yyy-mm-dd_hh_mm_ss.log
    14264, 8756, 2017-10-01 17:16:36.645, TL_INFO, , Other, Diagnostic data
    RemoteBwCheckResult 0 ConnectivityDiagnosticMessage
    ICEWarn="0x80000";ICEWarnEx="0x1";LocalSite="192.168.2.184:9178";PortRange="1025:65000";LocalLocation="2";
    RemoteLocation="0";FederationType="0";NetworkName="Network3";Interfaces="0x12";IceRole="1";RtpRtcpMux="0";
    MediaDllVersion="6.0.8808.21";MrDnsU="SEAANTED01.antuit.com";MrResU="0";MrDnsCacheReadAttempt="1"
    MediaDiagnosticMessage NetworkErr="no error";ErrTime="0";RTPSeq="0";SeqDelta="0";RTPTime="0";RTCPTime="0";
    TransptRecvErr="0x0";RecvErrTime="0";TransptSendErr="0x0";SendErrTime="0";InterfacesStall="0x0";
    InterfacesConnCheck="0x0";
    MrDnsU="SEAANTED01.antuit.com";MrResU="0";MrDnsCacheReadAttempt="1"

    14264, 8756, 2017-10-01 17:16:21.878, TL_INFO, , Other, Processing MediaPlatformConfig method - AddIceServer
    14264, 8756, 2017-10-01 17:16:21.878, TL_NOISE, , Other, Method enter
    14264, 8756, 2017-10-01 17:16:21.878, TL_INFO, , Other, Adding ICE server type 1 name SEAANTED01.antuit.com port 3478

In our case there was no DNS entry for SEAANTED01.antuit.com and once we added DNS record, web app started working as expected.

There may be few other scenarios where Web app might not be functioning as expected, check out this blog for other scenarios – https://www.msxfaq.de/lync/trace/skypefb_webapp_debugging.htm