SS7 Headers
What are SS7 Headers?
SS7 headers are used to set message information & send via SS7 protocol.
NSG maps SS7 information elements into SS7/SIP messages in order to pass specific SS7 parameters to the end user.
NSG usesSS7 headers to pass SS7 variables from SS7->SS7 & SS7->SIP (i.e. CIC, NADI, RDNIS..etc)
Passing information from SS7→SS7/SS7→SIP
By default if NSG receives a SS7 message with any of the SS7-Headers defined below and the SS7-Headers feature is enabled, NSG will automatically populate the associated SS7 messages with the specified values. A SS7-Header will only be considered if it is properly formed, and matches the string found in the "SS7-Header" column below, and is case-insensitive.
FreeSWITCH - How to Use SS7 Headers
SS7->SIP (Receiving SS7 Header From NSG)
SS7 header will be stored in the FreeSWITCH variable "freetdm_Z" with Z being the SS7 header.
The example below will print to the log/console the value of the SS7 header that contains the cic number the call is on.
Example
<action application="log" data="The CIC Number Is: [${freetdm_ss7_cic}]"/>
SIP->SS7 (Sending SS7 Header To NSG)
You can populate an SS7 header by using the "export" application in FreeSWITCH.
The example below shows how to set the RDNIS NADI value to 4.
Example
<action application="export" data="freetdm_ss7_rdnis_nadi=4"/>
NOTE
While setting SS7 header from dialplan we always needs to use freetdm as a prefix to SS7 Headers for example if we need to set redirection nadi then in dialplan we need to use variable as freetdm_Z as explained before as shown below:
<action application="export" data="freetdm_ss7_rdnis_nadi=4"/>
SS7-> SS7 means when parameters can be exported from SS7 to SS7.
SS7->SIP means when parameters can be exported form SS7 to SIP .
If "Y" than that parameter can be set and exported/set. If "N" then it is not.
Complete List of SS7 Headers
General
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_clg_num | Y | N | |
ss7_orig_clg_num | Y | N | |
ss7_iam_fwd_ind_hex | Y | Y | |
ss7_iam_nature_connection_hex | Y | Y | |
ss7_iam_priority | Y | Y | |
ss7_screen_ind | Y | Y | |
ss7_pres_ind | Y | Y | |
ss7_access_transport_urlenc | Y | Y | |
ss7_hopCounter_val | Y | Y | |
ss7_usr2UsrInfo_val | Y | Y | |
ss7_num_port_fwd_info_status_ind | Y | N | |
ss7_num_port_fwd_info_status_ext | Y | N |
Advanced
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_cic | Y | N | |
ss7_opc | Y | N | |
ss7_clg_nadi | Y | Y | |
ss7_cld_nadi | Y | Y |
Redirected Dialed Number
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_rdnis_digits | Y | Y | |
ss7_rdnis_nadi | Y | Y | |
ss7_rdnis_plan | Y | Y | |
ss7_rdnis_screen_ind | Y | Y | |
ss7_rdnis_pres_ind | Y | Y |
Generic Number/Generic Number Repeated
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_gn_digits / ss7_gn_repeated_digits | Y | Y | |
ss7_gn_numqual / ss7_gn_repeated_numqual | Y | Y | |
ss7_gn_nadi / ss7_gn_repeated_nadi | Y | Y | |
ss7_gn_screen_ind / ss7_gn_repeated_screen_ind | Y | Y | |
ss7_gn_pres_ind / ss7_gn_repeated_pres_ind | Y | Y | |
ss7_gn_npi / ss7_gn_repeated_npi | Y | Y | |
ss7_gn_num_inc_ind / | Y | Y |
Location Number
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_loc_digits | Y | Y | |
ss7_loc_screen_ind | Y | Y | |
ss7_loc_pres_ind | Y | Y | |
ss7_loc_nadi | Y | Y |
Redirection Information Number
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_rdinfo_indicator | Y | Y | |
ss7_rdinfo_orig | Y | Y | |
ss7_rdinfo_count | Y | Y | |
ss7_rdinfo_reason | Y | Y |
Original Called Number
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_ocn | Y | Y | |
ss7_ocn_nadi | Y | Y | |
ss7_ocn_plan | Y | Y | |
ss7_ocn_pres | Y | Y |
IAM User Service Information Parameter
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_iam_usi_trans_cap | Y | N | |
ss7_iam_usi_code_standard | Y | N | |
ss7_iam_usi_trans_mode | Y | N | |
ss7_iam_usi_trans_rate_0 | Y | N | |
ss7_iam_usi_layer1_ident | Y | N | |
ss7_iam_usi_layer1_prot | Y | N | |
ss7_iam_usi_layer2_ident | Y | N | |
ss7_iam_usi_layer2_prot | Y | N | |
ss7_iam_usi_layer3_ident | Y | N | |
ss7_iam_usi_layer3_prot | Y | N | |
ss7_iam_usi_chan_struct | Y | N | |
ss7_iam_usi_config | Y | N | |
ss7_iam_usi_establish | Y | N | |
ss7_iam_usi_symmetry | Y | N | |
ss7_iam_usi_rate_multiplier | Y | N |
ITX Message Parameter
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_itx_charge_unit | Charge Unit Number | Y | N |
ss7_itx_msg_num | Message Number | Y | N |
SS7 UK Parameters
Presentation Number
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_pres_num_digits | Y | Y | |
ss7_pres_num_nadi | Y | Y | |
ss7_pres_num_screen_ind | Y | Y | |
ss7_pres_num_pres_ind | Y | Y | |
ss7_pres_num_npi | Y | Y | |
ss7_pres_num_pref_plan_ind | Y | Y |
Link by Link National Forward Call Indicator
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_fci_lxl_rci | Y | Y | |
ss7_fci_lxl_isi | Y | Y |
National Forward Call Indicator
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_nfci_cli_blocking_ind | Y | Y | |
ss7_nfci_nw_trans_addr_ind | Y | Y |
Divert Line ID
SS7-Header | Description | SS7->SS7 | SS7->SIP |
ss7_divertlineid_digits | Y | Y | |
ss7_divertlineid_nadi | Y | Y | |
ss7_divertlineid_screen_ind | Y | Y | |
ss7_divertlineid_pres_ind | Y | Y | |
ss7_divertlineid_plan | Y | Y | |
ss7_divertlineid_incomp_ind | Y | Y |