[{"name":"S2-2108297","title":"LS from GSMA 5GJA: LS to 3GPP on IMS Data Channel Architecture","source":"GSMA 5GJA","contact":"Xueqian Bai","contact-id":92286,"tdoctype":"LS in","for":"Action","abstract":"Background: GSMA NG 5GJA Data Channel Task Force (DCTF) has completed the NG.129 IMS Data Channel whitepaper which is up for GSMA approval, means it is not yet publicly available. The white paper aims to provide the first complete analysis of IMS data channel technology, educate the industry about IMS data channel capabilities, and identify any outstanding issues. It is based on the IMS Data Channel defined in 3GPP TS 26.114 (Release 16). This LS is sent to SA WG2\/SA WG4 in order to address some open questions raised by the Data Channel Task Force members. Annex A DCS Architecture of the GSMA NG.129 - IMS Data Channel White Paper will be publicly available for further information once the document is approved and published by GSMA. Discussion: GSMA NG.129 elaborates on IMS data channel architectural details. The relationships between 3GPP network functions are shown in Figure 1 and use some terms which are still to be specified by the appropriate standardisation organisation. The GSMA NG 5GJA DCTF concluded that: ? The Data Channel control function (part of the Data Channel Server) acts as the control function for IMS Data Channel for the data channel bootstrap and e2e media. ? The DC control function can also terminate the media endpoint for IMS Data Channel media. ? The Data Channel Media function (DCM\/MRF) relays the media to\/from the Data Channel control function. ? Either - a new new interface (IF1) handling the interaction between the Data Channel control function and the Data Channel media function is needed, or - a new Network Function encompassing functionalities from different existing entities, for example, from MRF, IMS AS, Data Channel control function is needed. ? The Data Channel Media function (DCM\/MRF) relays the Data Channel media between Mb interface and IF1 interface. ? The Data Channel Control Function is not acting as SIP AS. The GSMA NG 5GJA DCTF has not been able to come to a conclusion on the following aspects: Question-1: Is there a need for a new IMS Data Channel media function (realized by a new NF named as DCM-Data Channel Media) or can the existing MRF be enhanced to meet all the requirements for IMS data channel media? NOTE: It's assumed that when the definition of MRF is enhanced to support the Data Channel media function, it does not mean that any deployed MRF would need to be enhanced. Instead an MRF for the IMS Data Channel media can be deployed alongside an existing MRF handling RTP (audio\/video) media. Question-2: If a new NF is defined, should the IMS AS be enhanced to support SBI (not shown in the DC architecture Figure 1) to enable the interaction between the Data Channel Control Function and the Data Channel Media function (DCM\/MRF) via an IMS AS? Question-3: Is the assumption correct that IF6 (DC Control API) and IF1 (DC media) between Operator IMS and the DCS would not need to be defined in 3GPP, and thus could be defined in another standardization body?. Action: GSMA NG 5GJA kindly asks SA WG2 and SA WG4 to provide answers to the above questions.","secretary_remarks":"Responses drafted in S2-2108901 and S2-2108907. Postponed","agenda_item_sort_order":38,"ainumber":"7.13","ainame":"Enhanced IMS to 5GC Integration (eIMS5G_SBA)","tdoc_agenda_sort_order":12310,"status":"postponed","reservation_date":"2021-10-29 06:41:20","uploaded":"2021-11-05 14:17:03","revisionof":"","revisedto":"S2-2200015","release":"","crspec":"","crspecversion":"","workitem":"","crnumber":"","crrevision":"","crcategory":"","tsg_crp":"","lsreplyto":"","lsto":"SA WG2, SA WG4","Cc":"","lsoriginalls":"5GJA18_109r1","lsreply":"","link":"https:\/\/www.3gpp.org\/ftp\/tsg_sa\/WG2_Arch\/TSGS2_148E_Electronic_2021-11\/Docs\/S2-2108297.zip","group":"S2","meeting":"S2-148-e","year":2021,"uicc_affected":null,"me_affected":null,"ran_affected":null,"cn_affected":null,"clauses_affected":null,"crsinpack":null,"crsinpacknumber":0},
{"name":"S2-2108907","title":"[DRAFT] Reply LS on IMS Data Channel Architecture","source":"China Mobile","contact":"Yi Jiang","contact-id":40863,"tdoctype":"LS out","for":"Approval","abstract":"Reply LS on IMS architecture supporting data channel to GSMA NG 5GJA","secretary_remarks":"Response to S2-2108297. Postponed","agenda_item_sort_order":38,"ainumber":"7.13","ainame":"Enhanced IMS to 5GC Integration (eIMS5G_SBA)","tdoc_agenda_sort_order":12320,"status":"postponed","reservation_date":"2021-11-08 15:21:56","uploaded":"2021-11-08 15:51:17","revisionof":"","revisedto":"","release":"","crspec":"","crspecversion":"","workitem":"","crnumber":"","crrevision":"","crcategory":"","tsg_crp":"","lsreplyto":"","lsto":"GSMA NG 5GJA","Cc":"SA WG4","lsoriginalls":"","lsreply":"","link":"https:\/\/www.3gpp.org\/ftp\/tsg_sa\/WG2_Arch\/TSGS2_148E_Electronic_2021-11\/Docs\/S2-2108907.zip","group":"S2","meeting":"S2-148-e","year":2021,"uicc_affected":null,"me_affected":null,"ran_affected":null,"cn_affected":null,"clauses_affected":null,"crsinpack":null,"crsinpacknumber":0}]