· The ESM information request procedure is used by the network to retrieve ESM information, i.e. protocol configuration options, APN, or both from the UE during the attach procedure if the UE has indicated (in the PDN CONNECTIVITY REQUEST) that it has ESM information that needs to be sent security protected.
· The purpose of this procedure is to provide privacy for the ESM information if ciphering is enabled in the network.
· The network initiates the ESM information request procedure by sending a ESM INFORMATION REQUEST message to the UE and starts the timer T3489.
· This message shall be sent only after the security context has been setup, and if the ESM information transfer flag has been set in the PDN CONNECTIVITY REQUEST message.
· The MME shall set the EPS bearer identity of the ESM INFORMATION REQUEST message to the value "no EPS bearer identity assigned" and include the PTI from the associated PDN CONNECTIVITY REQUEST message.
· After receiving the ESM INFORMATION REQUEST message, the UE shall send an ESM INFORMATION RESPONSE message to the network.
· The UE shall include all the protocol configuration options that need to be transferred security protected, and APN if required, to the network in the ESM INFORMATION RESPONSE (see the example below)message.
· The UE shall set the EPS bearer identity of the ESM INFORMATION RESPONSE message to the value "no EPS bearer identity assigned" and include the PTI from the ESM INFORMATION REQUEST message
Reference 3GPP TS 24.301
Example: ESM INFORMATION REQUEST message
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Example: ESM INFORMATION RESPONSE message
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Hi Kumar,
ReplyDeletei am a big follower of your blog but i dont see any updates in this.
Please keep updating your blog and keep up the good work.
Regards.
Sam
I love your blog.It makes LTE newbies like me smile.
ReplyDeleteIs possible that a UE doesn't send ESM Transfer flag? If Yes, wich will the UE bheaviour reguarding the APN?
ReplyDeleteThanks a lot
Hi , in that case that apn should be default set in the subscription data base then the attach will also work.
DeleteIs possible that a UE doesn't send ESM Transfer flag? If Yes, wich will the UE bheaviour reguarding the APN?
ReplyDeleteThanks a lot
Yes it is possible to disable ESM transfer flag, which can be done in UE side setting. By doing that UE will set info_trans_flag_incl = 0 (0x0) in Attach request and Network will not send any ESM information request Msg to UE. then Network will assign available default APN like INTERNET PDN.
ReplyDeleteWhat settings needs to be done UE side for disabling the ESM information message?
ReplyDeleteDelete all APNs in UE. Then in attach request msg, this" info_trans_flag_incl =0 " flag will set to 0 and send to network in OTA, network knows that, u don't have any apn. so It will not send any ESM information request msg to UE. and it will assign default apn.
DeleteGreat...Have you tried this?
DeletePlease anybody tell me if I got info_trans_flag_incl =0 in attach request though default APN not deleted form the UE. Then it will be issue in UE or not ?
ReplyDeleteHere S.Korea SKT using info_trans_flag_incl =0, so UE
ReplyDelete07:16:38.382 [0xB0ED] LTE NAS EMM Plain OTA Outgoing Message
pkt_version = 1 (0x1)
rel_number = 9 (0x9)
rel_version_major = 5 (0x5)
rel_version_minor = 0 (0x0)
security_header_or_skip_ind = 0 (0x0)
prot_disc = 7 (0x7) (EPS mobility management messages)
msg_type = 65 (0x41) (Attach request)
lte_emm_msg
emm_attach_request
tsc = 0 (0x0) (cached sec context)
nas_key_set_id = 4 (0x4)
att_type = 2 (0x2) (combined EPS/IMSI attach)
eps_mob_id
id_type = 6 (0x6) (GUTI)
odd_even_ind = 0 (0x0)
Guti_1111 = 15 (0xf)
mcc_1 = 4 (0x4)
mcc_2 = 5 (0x5)
mcc_3 = 0 (0x0)
mnc_3 = 15 (0xf)
mnc_1 = 0 (0x0)
mnc_2 = 5 (0x5)
MME_group_id = 32769 (0x8001)
MME_code = 17 (0x11)
m_tmsi = 3627735295 (0xd83ad8ff)
esm_msg_container
eps_bearer_id_or_skip_id = 0 (0x0)
prot_disc = 2 (0x2) (EPS session management messages)
trans_id = 2 (0x2)
msg_type = 208 (0xd0) (PDN connectivity request)
lte_esm_msg
pdn_connectivity_req
pdn_type = 3 (0x3) (Ipv4v6)
req_type = 1 (0x1) (initial request)
info_trans_flag_incl = 0 (0x0)
access_pt_name_incl = 0 (0x0)
prot_config_incl = 1 (0x1)
prot_config
ext = 1 (0x1)
conf_prot = 0 (0x0)
num_recs = 1 (0x1)
sm_prot[0]
protocol_id = 32801 (0x8021) (IPCP)
prot_len = 16 (0x10)
ipcp_prot
ipcp_prot_id = 1 (0x1) (CONF_REQ)
identifier = 0 (0x0)
rfc1332_conf_req
num_options = 2 (0x2)
conf_options[0]
type = 129 (0x81)
rfc1877_primary_dns_server_add
length = 6 (0x6)
ip_addr = 0 (0x0) (0.0.0.0)
conf_options[1]
type = 131 (0x83)
rfc1877_sec_dns_server_add
length = 6 (0x6)
ip_addr = 0 (0x0) (0.0.0.0)
There are two apn for IMS and data, NW accept with ims apn first all the time as their nw.
ReplyDeleteHi all can anboany explain what is LPP = 1 in attach request and if LPP = 0 what will be impact on User UE. Is this an issue ? If I got LPP = 0
ReplyDeleteenojoy the life bro .leave the queries and study
Delete4G “Attach” failure in S1 MME interface with “Requested service option is not subscribed=33” when ESM Information transfer flag is set...why it happens and what is the solution for that
ReplyDeletethanks for information
ReplyDeleteHow can I solve it
ReplyDeleteit seam that if ESM is enabled in MME , So during attach UE should reply by ESM response otherwise MME will reject the attach of this UE ...
ReplyDeleteEven I tried to remove all APN from UE , but it still can not attach ..., anybody have idea ...
ReplyDelete