Yearly Archives: 2016


So manny things happened in 2016, good things, bad things, happy things, sad things, and I was busy in my own so called “The most comfortable state of mind”, but I was cheating myself actually. Now, 2017 is approaching, new year brings with it new opportunities and excuses to make […]

New year, new starts, new beginnings



August 20, a cloudless sunny summer day, PM2.5 35, a very clear and clean day considering we are living in China, in Shanghai. 7 am of that bright day, a little angel came to our life. and, today, we named her 韦曦. 曦 means dawn in Chinese, and because her […]

Little angel falled to our home



Sympton: ——————————————- TE40 caller : 202.102.40.211, E.164: 02510000 TE40 caller : 192.168.0.109,  E.164: 02510000 H600 callee : 192.168.0.105,  E.164: 654320 VP9650: 202.102.40.219 Pcap file was captured on H600 side. All exchanged signaling commands between H600 and VP9650: ->SCI <-SCR,facility ->setup <-ARQ ->ACF <-alerting,connect ->facility ->TCS …Twenty seconds later… –>ReleaseComplete, DRQ […]

An issue when collaborating with HUAWEI VP9650 with H.460



Both ZTE T800 and HUAWEI TEx0 claim to have T.140 supported, but when I digging into these entities by running some tests between T800, TE40 and TE60, my current status is I’m not persuaded. Maybe only because I don’t know how to configure them to make T.140 enabled. Here is some T.140 related information, and my steps to analysis to the protocols of HUAWEI TEx0 and ZTE T800. A screen shot of HUAWEI TEx0’s administration manual about T.140. Source: http://support.huawei.com/ehedex/pages/DOC1000063904NZD1231E/01/DOC1000063904NZD1231E/01/resources/webhlp/te_webhlp_00005.html#te_webhlp_00005__tb5 1. T.140 related standard documents 1)T-REC-H.323-200002-S!AnnG!PDF-E.pdf 2)T-REC-H.224-200501-I!!PDF-E.pdf 3)T-REC-T.140-199802-I!!PDF-E.pdf 5)T-REC-T.140-200002-I!Add1!PDF-E.pdf 6)RFC4103 – RTP Payload for Text Conversation.pdf 2. Major descriptions of implementing T.140 T.140 related descriptions in T-REC-H.323-200002-S!AnnG!PDF-E. 1) H.245 TCS for T.140 In the capabilities exchange, when using a reliable channel, specify: DataApplicationCapability.application = t140 DataProtocolCapability = tcp In the capabilities exchange, when using an unreliable channel, specify: DataApplicationCapability.application = t140 DataProtocolCapability = udp 2) H.245 Open Logical Channel In the Open Logical Channel procedure, specify: OpenLogicalChannel.forwardLogicalChannelParameters = dataType DataType = data And select a reliable or unreliable channel for the transfer of T.140 data by specifying the DataApplicationCapability and the DataProtocolCapability as above. According to the description in T-REC-H.224-200501-I!!PDF-E, there should be only one H.221 channel, we can still send multiple protocols, like FECC, T.120 and T.140, in one single channel, this type of channel has a name: H.221 MLP data channel. 3) Packetization of T.140 data Reliable TCP mode: skipped because don’t find any newlly established TCP connections. UnReliable mode: I do find an H.224 capability in both of these entities, since there is no OLC requests other than Audio, Video, and H.224 data. Let’s suppose they are re-using the H.221 MLP data channel for both FECC and T.140 transmission. 4) H.224 protocol octet structure 5) H.224 -Standard Client ID Table 3. H.224 data packets sending between TE60 and T800 I managed to extract the H.224 data packets from the PCAP file. And they are like these: 7e 7e 7e 00 86 c0 00 00 00 00 00 03 40 00 81 a8 e8 0f b2 07 db 07 9f 9f 9f bf ff Explain the packet by the standard document’s description: […]

Does ZTE T800 and HUAWEI TEx0 support T.140?



5
Got mails continuously from everywhere throwing question to me about AAC audio in H.323. So I arranged this post to example my previous posts: http://rg4.net/archives/1480.html, http://rg4.net/archives/1126.html, http://rg4.net/archives/1112.html The pcap file for this example can be downloaded here: HUAWEI_TE600-vs-ZTE_T800.pcapnp Here it is. 1. Basic knowledge: AAC LD descriptions in 14496-3 It operates at up […]

An example of AAC capability in H.245