Need some help on content type header ! | Search |
NowSMS Support Forums ⬆ MMS & SMS Technical Discussions (unsupported) ⬆ Archive through March 23, 2004 ⬆ |
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Author | Message | |||
shwetha Unregistered guest |
Hi, i am having problems understanding the content type header... 84 A3 01 04 03 03 83 81 EA 6D 70 34 in the above, 84- content type assignment number A3- multipart/mixed 01- number of multipart entries 04 -headers length 03 - data length 03 83 81 EA - content type + headers 6d 70 34 - data i know this because i took a worked out example from somewhere.. what my question is , is that how do i know that: * the number of entries is 01 ? this field is a Uintvar, so it does not have a fixed length. how do i find out the length of this field? * the same question for the following two fields - ie headerslen and data length ? one more doubt i have - what is the maximum number of multipart entries ? i'm working on a project and i'm relaly stuck.. could you please enlighten me ?! thanks | |||
shwetha Unregistered guest |
Hi, i'm back with more doubts.. i have some difficulty getting the big picture of the content type headers. please read what ive written and confirm whether it is right or not.. in the MMS PDUS like M-Send.req and M-Retrieve.conf, the last MMS field is contenttype. now, the format for any MMS field is the MMS field name assignment followed by the value of that field. going by that, the following would be the order for the content type field: 1. field name assignment = 84 2. value of content type field : this according to the WSP spec would be: a. number of entries - b. entry1 c. entry2 and so on.... now, each entry would have : i) headerslen ii) datalen iii) content type vi) headers v) data this pattern would repeat for every multipart entry, right ? now, according to WSP spec "header encoding" , content-type field = content general-form | constrained media .... how would i relate the architecture of the multipart< which i have listed above> with those specified in the WSP specs? could u also explain this example : 84 1F 21 B3 8A 3C...3E 00 89 61 70 70..66 00 84 = mms assignment number 1F 21 - length-quote length B3 - multipart/related 8A - start followed by the value 89 - type followed by the value. my problem is : * where is the number of multipart entries ? * where is the headerslen, datalen ? * is B3 the content type ? * 8A and 89 are the headers ?? * so after the above stream , the data would follow ? please help me, as i am not able to get the big picture at all... thank you. | |||
shwetha Unregistered guest |
hi, is this correct : [mms field assignment no=84][field value] field value = constrained media | content-general-type constrained media = text string or short integer ( Table 40 of WSP spec) content-gen-type = value length media-type media-type = text string or integer (Table 40) followed by 0 or more Parameters. After this,the MMS headers finish and then the multipart message body begins.... ? here: [no of entries] [entry1][entry2].... each entry : [headerslen][datalen][contenttype][headers][data] is this correct so far ? in the above, the contenttype assignments i obtain from Table 40 of WSP spec ? and table 38 would give me the headers and the parameters? i 'd be grateful if u can sort this out for me. | |||
Emanuele Vittore New member Username: Emavit Post Number: 15 Registered: 10-2003 |
Do you use udp to send MMS to wap gateway? and do you send HTTP CONNECT ? In your thread you speak of WSP PDU ? | |||
shwetha Unregistered guest |
hi, i am talking of MMS PDU.... at the moment i am just trying to figure out how the content type is structured, that s all. for that , i just took a random MMS PDU hex dump . | |||
Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 1045 Registered: 10-2002 |
Maybe someone else can help you with the other questions, as I don't have any time at present. But for uintvar, see the following threads: http://support.nowsms.com/discus/messages/12/522.html http://support.nowsms.com/discus/messages/12/857.html http://support.nowsms.com/discus/messages/12/470.html | |||
Jonatan Unregistered guest |
I'm also stuck on the content-type decoding. My script is now able to decode everything but the contenttype, if anyone could explain shwetha's questions I would be very greatful. BTW, I'll get back to this thread when I cracked it if none has answered by then and if I remember /jonatan | |||
Bryce Norwood - NowSMS Support Board Administrator Username: Bryce Post Number: 2145 Registered: 10-2002 |
Jonatan, There's not realy enough information in Shwetha's questions to allow me to answer them. In the first message, he appears to have things decoded correctly, just has doubts about uintvar encoding and how to know when a uintvar value spans multiple bytes. The explanation of uintvar encoding in WSP Section 8.1.2 is quite clear ... if the continue bit is set (high bit - | 80), then the uintvar value continues into the next byte. In the second example, he asks the following questions: * where is the number of multipart entries ? In the content. He only displays the content-type header for the wap.multipart.* wrapper. * where is the headerslen, datalen ? In the content. * is B3 the content type? Yes. * 8A and 89 are the headers ?? No, they are parameter values on the content type. * so after the above stream , the data would follow The wap.multipart.related data, yes. The wap.multipart.data has its own headers ... the format being defined in WSP Section 8.5. -bn |