Introduction:

The SMSINDIAHUB Messaging Platform uses the SMPP v3.4 Protocol Specification Issue 1.5, However it has been designed to be backward compatible with SMPP v3.3.

This document should be read in conjunction with SMPP v3.4 Specification v1.5 and assumes with SMPP a level of familiarity functionality. All the TSP’s have been mandated to comply to the TCCCPR regulation of 2019 by TRAI. In regards to the same, there are several changes which have been triggered in the way the A2P SMS business is being performed.

Scrubbing Model

For understanding the preference scrubbing model, we would need to establish certain definitions and their inter-relationships.

Note:

The terms ‘Sender’, ‘Entity’ and ‘Principal Entity’ will be used interchangeably in this document depending on the context however they mean the same

Terms	Definition and Remark
Transaction	Check for Sender registration, header registration and template
Service Implicit	Check for Sender registration, header registration and template
Service Explicit	Check for Sender registration, header registration, check for consent and template If the consent scrub fails then preferences will be checked w.r.t Fully Block. If preference scrub passes (i.e. Customer is not on FULLY BLOCK) then the message will be delivered. If both of these fail (i.e. Customer is on FULLY BLOCK), message will not be delivered.
Promotional	Check for Sender registration, header registration, check for consent and template If the consent scrub fails then preferences will be checked. If preference scrub passes then the message will be delivered. If both of these fails, message will not be delivered.

Terms	Definition and Remark
Sender/Principal Entity	As per the regulation – the definition is: “The person or entity who owns the telephone number or the header(s) that were used. A person or entity that publicly asserts or uses a Calling Line Identity (CLI) or the phone number(s) referred to in the communication, except where such assertion is fraudulent The person who sent the message or made a voice call, caused the message to be sent or the voice call to be made or authorized the sending of the message or making of the voice call The person or legal entity dealing with goods, or services, or land or property, or a business or investment opportunity that is offered or promoted; except where such entity maintains a distinct legal identity for the division or line of business dealing with offered goods, services or opportunity, in which case such division or line of business” Interpretation for implementation: When they will register on DLT – they will be given a unique ID – “Principal Entity ID (PE ID)”Have one category from the categories listed in the preference regulations (e.g. Real Estate, Health, and Education etc.). An Entity can have association with only one type of category of businessEntity will own Headers, Registered Templates
Telemarketer	As per regulation – means a person or legal entity engaged in the activity of transmission or delivery of commercial communication or scrubbing or aggregation. Interpretation for implementation: Once they register on DLT – they will be given a unique ID – “Telemarketer ID (TM ID)”They cannot own headers or templatesThey will have a billing relationship with the Operator.They do not have to prove their relationship with an entity to the Operator. They will directly send messages and the Operator will accept them for scrubbing on DLT. Based on scrubbing output the SMS will either be rejected or delivery will be attempted
Header/CLI	Header can be associated to Entities only and not to any TMHeader can be of two categories – Promotional or OthersOthers will encompass – government, stocks, transaction, service etc. all types of headers which are not promotional
Content Template (Script)	This is the message text that the sender wishes to send to the subscriber. It may contain some fixed part and variable partOnce it is registered on DLT – a unique ID will be associated with this. This ID is called “Content Template ID”Each content template will need to be associated with a header using which it can be sent

Terms	Definition and Remark
Consent	As per regulation – “Consent” means any voluntary permission given by the customer to sender to receive commercial communication related to specific purpose, product or service. Consent may be explicit or inferred as defined in these regulations Interpretation for implementation: There are total of three separate processes associated with consent: Consent Acquisition: process where the subscriber or the sender will initiate a consent acquisition process. The process will be initiated with bulk consent upload – other channels will be enabled subsequentlyConsent verification: process via which the TAP will verify the consent acquisition request received – Verification will be done by TAPConsent scrubbing: check whether the customer has provided the consent to the entity or notConsent will be stored in hashed format and encrypted format on DLT for added security measure
Consent Template	Means a template of content which is presented to the customer while acquiring his consent and clearly mentions purpose of the consent and details of sender When consent template is approved, consent template ID will be generated from DLT. When the subscriber gives the consent using the consent verification process, the consent template ID used to acquire it will be associated with the subscriber. This association of the consent template ID will be checked with the MSISDN for sending the message.
Preferences	Definition as per Regulation: “Means preference exercised by the customer to permit only a selected category of commercial communications out of available choices prescribed by relevant regulations” These preferences will map back to the category of business which the entity has selected during registration.

Figure below provides an understanding of scrubbing framework for preference scrubbing.

What will SIH Need to scrub from Entity?

The list below provides the minimum set needed for scrubbing.

PE ID (New)
Content Template ID (New)
CLI/Header (already part of request)
SMS Content (already part of request)

Sending a Message

How to send a message?

To Register on DLT to have – PE ID, Content Template ID and approved Header
For sending the messages, the entity can either approach SIH directly or come via any of their preferred TM who have connectivity with SIH.
There are three modes via which the messages can be sent using SIH as an Aggregator.

Using SIH Web Interface
Using SMPP interface
Using SIH API interface

SMPP Interface

The SIH SMPP interface is provide the below facility.

Connectivity between Telemarketer and Operator
PDU validation check on Header, MSISDN, PE DLT ID, TM ID, Template ID
Data Encoding (DCS)
Scrubbing

For using the SMPP interface of SIH, there will four new mandatory parameters introduced in the SMPP PDU

Parameter	Reason
Principal Entity ID (PE ID)	This will help the system execute overall scrubbing modelIn case of future customer complaints, PE will be held responsible for any message which has goneThis is also going to be used for the identity assertion by the TM for having an authority of sending the message on behalf of the PE.
Template ID	To check registration status of the messageTo perform scrubbing
Telemarketer ID (TM ID)	This is field will define the billing relation with the Operator. If a PE is having a direct billing relationship with the Operator, then in that case PE ID = TM IDThis will be used for executing billing.This field is also used to check the authenticity of the Telemarketer and its identity assertion.

SMPP Protocol:

SMPP will contain optional TLV fields which can be used for the purpose of submission of additional parameters. To integrate fully, PE ID would have to add the same TLVs on their end. This additional TLVs will need to be added within every message in Submit SM.

Ref to new TLV Parameter, PE need to send the PE ID & TEMPLATE ID under the Two Optional Tag Value HEX 0x1400 & 0x1401.

Sample PDU for reference:

PDU:Submit_SM

BINARY:00000062000000040000000000000007000000424E4B425A5200000039 313931353835353539313500000000000001000000137465737420444C5420706C617

466726F6D20321490000631323334350014920006343536373800147C000400001C31c

ommand_length:98comman_d:0x00000004command_status:0x00000000sequenc e_number:7service_type:src_ton:0x00src_npi:0x00src_address:XXXXXXdest_ton:0x0 0dest_npi:0x00dest_address:919158XXXXXXesm_class:0x00protocol_id:0x00priority_ flag:0x00schedule_delivery_time:validity_period:registered_delivery:0x01replace_if_ present:0x00data_coding:t0x00sm_default_msg_id:0x00sm_length:0x0013 short

_message:7465737420444c5420706c617466726f6d2032 text:test DLTplatfrom 2 ExtraOptional 0x1400:(oct: (tlv: 5120) 313233343500) ExtraOptional0x1401:(oct:

(tlv:5121) 343536373800)

Hereafter, the revised definition of TLV fields are as follows:

Principal Entity ID TLV: 0x1400 (Hex), string, len = 30: this will be a unique client identifier on DLT platform.

Content Template ID TLV: 0x1401 (Hex), string, len = 30: this data corresponds to the content Template ID received when template is registered on DLT platform.

Sample PCAP screenshot is attached below which provides the information for SMPP new parameters:

Connectivity

Clients may connect to the SMSINDIAHUB Messaging Platform Server multiple numbers of times. This may be of importance if the client wishes to deploy multiple applications simultaneously. To connect to the SMSINDIAHUB Messaging Platform one needs to specify the following parameters:

IP Address and Port: This is the TCP/IP endpoint on which the ESME should connect to the SMSINDIAHUB Messaging Platform.

system_id: This is the username of your account configured on the SMSINDIAHUB Messaging Platform.

Password: Password for the above account. Required for security reasons to prevent unauthorized access to your account.

system_type: This field is not used by us, hence set to null.

interface_version: The client application should connect with the interface_version field set to 0x34 (52 decimal), if it is using SMPP v3.4, otherwise the SMSINDIAHUB Messaging Platform assumes that the application is using SMPP v3.3.

If the application uses SMPP v3.3 then the optional fields cannot be used. These optional fields may be required to implement extra facilities like long SMS, etc.

enquire_link: The application should issue an enquire_link every minute. This will ensure the link stays active even when it is not in use. The SMSINDIAHUB Messaging Platform will automatically disconnect any link which is inactive for more than 5 min.

Submitting Messages

Submission Types

Messages may be submitted with either submit_sm or data_sm, using either the short_message or message_payload fields. The message length may not exceed the byte limit for the network that the message is being sent to (for example 140 bytes on GSM networks).

The SMSINDIAHUB Messaging Platform does not support submit_multi. If the same message has to be sent to multiple destinations, each message must be sent separately.

These are optional parameters are also not supported.

Concatenated messages are supported by using the User Data Header (UDH), which is included in the message size byte limit.

Submit Responses

A positive response to a ‘submit’ will contain an error code of zero and a non-null message reference.

A negative response will contain a SMSINDIAHUB vendor specific error code. The complete set of SMPP Error Codes and their associated values are defined in the following table.

Table 1 – SMPP Submission Error Codes

Error Code	Value	Description
ESME_ROK	0x00000000	No error.
ESME_RINVMSGLEN	0x00000001	Message length is invalid.
ESME_RINVCMDLEN	0x00000002	Command length is invalid.
ESME_RINVCMDID	0x00000003	Invalid command ID.
ESME_RINVBNDSTS	0x00000004	Incorrect BIND status for given command.
ESME_RALYBND	0x00000005	ESME already in bound state.
ESME_RINVPRTFLG	0x00000006	Invalid priority flag.
ESME_RINVREGDLVFLG	0x00000007	Invalid registered delivery flag.
ESME_RSYSERR	0x00000008	System error.
ESME_RINVSRCADR	0x0000000A	Invalid source address.
ESME_RINVDSTADR	0x0000000B	Invalid destination address.
ESME_RINVMSGID	0x0000000C	Message ID is invalid.
ESME_RBINDFAIL	0x0000000D	Bind failed.
ESME_RINVPASWD	0x0000000E	Invalid password.
ESME_RINVSYSID	0x0000000F	Invalid system ID.

Error Code	Value	Description
ESME_RINVSERTYP	0x00000015	Invalid service type.
ESME_RINVESMCLASS	0x00000043	Invalid esm_class field data.
ESME_RSUBMITFAIL	0x00000045	submit_sm failed.
ESME_RINVSRCTON	0x00000048	Invalid source address TON.
ESME_RINVSRCNPI	0x00000049	Invalid Source address NPI.
ESME_RINVDSTTON	0x00000050	Invalid destination address TON.
ESME_RINVDSTNPI	0x00000051	Invalid destination address NPI.
ESME_RINVSYSTYP	0x00000053	Invalid system_type field.
ESME_RTHROTTLED	0x00000058	Throttling error (ESME has exceeded allowed message limits)
ESME_RINVEXPIRY	0x00000062	Invalid message validity period (Expiry time).
ESME_RINVOPTPARSTREAM	0x000000C0	Error in the optional part of the PDU body.
ESME_ROPTPARNOTALLWD	0x000000C1	Optional parameter not allowed.
ESME_RINVPARLEN	0x000000C2	Invalid parameter length.
ESME_RMISSINGOPTPARAM	0x000000C3	Expected optional parameter missing.
ESME_RINVOPTPARAMVAL	0x000000C4	Invalid optional parameter value.
ESME_RDELIVERYFAILURE	0x000000FE	Delivery failure (used for data_sm_resp).
ESME_CREDIT_ERROR	0x00000401	Credits are over.
ESME_SPAM_MESSAGE	0x00000404	Spam content.
ESME_RINVSMLEN	0x00000405	Message length is exceeding in short_sm (e.g. for message type text max message length is 160 char).
ESME_RINVUDHLEN	0x00000406	Invalid UDH length indicator (Currently we allow 05, 06 with all type of data coding and 0b with data coding 245).
ESME_RINSMSEMPTY	0x00000407	Message body not found in either short_sm or message_payload.
ESME_RINDSTDND	0x00000408	Destination in DND.
ESME_RINSRCMSG	0x00000409	Invalid source/template.
ESME_RINSRCMSG	0x00000410	Source/template long message error code.
ESME_RINSRCMSG	0x00000411	Duplicate submission.
ESME_RINSRCMSG	0x00000412	Destination barred/Source barred.

Character Sets, Class and Data Coding

The SMSINDIAHUB Messaging Platform supports the following two types of data coding schemes:

GSM 03.38 Encoding (default)
Latin 1 (ISO-8859-1) encoding

The default character set is GSM 338. Although for data_coding=1 the character set

GSM 03.38 is supported it is NOT RECOMMENDED, as it is known to cause problems with character encoding. Please set data_coding = 3 for ISO-8859-1(if and only if told so explicitly) encoded messages and data_coding=0 for GSM 03.38 encoded messages.

For Unicode messages you have to set data_coding = 8 and the message is expected in UTF-16 Big Endean format.

Originators and Destination

The default originator type is full International MSISDN. Alpha numeric o network short code originators can be sent by using the following ton values in source_addr_ ton field.

Alpha-numeric	5
National / Network Short Code	3
International MSISDN	1

Destination Address types are not supported. They can be set to any value but are always interpreted as 1. This requires all the destination numbers to be sent in an international format without the leading 00.

Long Messages

Long messages as the name suggests are messages whose length exceeds the normal length imposed on short messages (160 for text and 70 for Unicode).

The user can send long messages via the SMSINDIAHUB Messaging Platform using the following two methods:

• Concatenated Messages

In this method the long message is sent in parts as multiple short messages which are then joined together on the mobile (If the mobile supports long messages, else each message part will be displayed as a separate message).

In this method the client sends the UDH (User Data Header) as part of the short_ message field. The UDH contains all the details required for the mobile join the parts and make the complete message at its end. In this method the client has to set the esm_class field in the submit_sm pdu to 0x43 (Store and Forward with UDHI)

• Message Payload

Here the SMSINDIAHUB Messaging Platform can accept a message with length up to 64K octets. In this method the client uses the optional message_payload of the submit_sm pdu. To use this method the client should set the interface_version to 0x34; else this field will not be available for sending messages.

Delivery Reports

The SMSINDIAHUB Messaging Platform will return a delivery report (Intermediate and/or final depending on the route) for a specific message to the client application when the registered_delivery field, while submitting the message, is set to 1. In order to retrieve the delivery report from our server the client will have to connect to the SMSINDIAHUB Messaging Platform in the receiver or transceiver mode.

Table 2 – Delivery Statuses

Status	Description
DELIVRD	Message delivered to device.
FAILED	Message could not be delivered.
EXPIRED	Message validity period expired, before any successful tries of submission.
UNDELIV	Message is undeliverable.
REJECTD	Message rejected.

Adding the error codes and statuses which can be returned by Messaging Platform.

Table 3 – Error Codes and Statuses

Status Error	Status	Description
000	DELIVRD	Delivered to SIM.
001	UNDELIV	Unidentified subscriber.
005	EXPIRED	Unidentified subscriber.
009	UNDELIV	Illegal subscriber.
011	UNDELIV	Tele service not provisioned.
012	UNDELIV	Illegal equipment.
013	UNDELIV	Call barred.
021	UNDELIV	Facility not supported.
027	EXPIRED	Absent subscriber.
031	EXPIRED	Subscriber busy for MT_SMS.
032	EXPIRED	SM-Delivery Failure.
034	EXPIRED	System failure.
035	UNDELIV	Data missing.
036	UNDELIV	Unexpected data value.
144	UNDELIV	Unrecognized component.
145	UNDELIV	Mistyped component.
146	UNDELIV	Body structured component.
160	EXPIRED	Duplicate invoke ID.
161	UNDELIV	Unrecognized operation.
162	UNDELIV	Mistyped parameter.

Status Error	Status	Description
163	EXPIRED	Resource limitation.
164	EXPIRED	Initiating release.
165	EXPIRED	Unrecognized linked ID.
166	EXPIRED	Linked response expected.
167	EXPIRED	Unexpected linked operation.
176	UNDELIV	Unrecognised invoke ID.
177	EXPIRED	Return result expected.
178	UNDELIV	Mistyped parameter.
192	EXPIRED	Unrecognised invoke ID.
193	EXPIRED	Return error unexpected.
194	UNDELIV	Unrecognised error.
195	UNDELIV	Unexpected error.
196	UNDELIV	Mistyped parameter.
200	UNDELIV	Unable to decode response.
201	EXPIRED	Provider abort.
202	UNDELIV	User abort.
203	EXPIRED	Timeout.
204	UNDELIV	API error.
205	UNDELIV	Unknown error.
404	REJECTD	Invalid message content.
408	REJECTD	DND error code.
409	REJECTD	Source/template error code.
410	REJECTD	Source/template long message error code.
411	REJECTD	Duplicate submission.
412	REJECTD	Destination barred/Source barred.
600	REJECTD	Entity not found.
601	REJECTD	Entity not registered.
602	REJECTD	Entity inactive.
603	REJECTD	Entity blacklisted.
604	REJECTD	Invalid entity ID.
605	REJECTD	Invalid optional parameter value.
606 – 609	REJECTD	Entity reserved.
610	REJECTD	Telemarketer not registered.
611	REJECTD	Telemarketer inactive.
612	REJECTD	Telemarketer blacklisted.
613	REJECTD	Invalid or missing TLV TM_ID.
614-619	REJECTD	Telemarketer reserved.
620	REJECTD	Header not found.
621	REJECTD	Header inactive.
622	REJECTD	Header blacklisted.

Status Error	Status	Description
623	REJECTD	EID not matched with header.
624	REJECTD	SMS type of header is not match template.
625	REJECTD	SMS type is not match with header/Template SMS type.
626-629	REJECTD	Header reserved.
630	REJECTD	Invalid or missing TLV template ID.
631	REJECTD	Template inactive.
632	REJECTD	Template blacklisted.
633	REJECTD	Template not matched.
634	REJECTD	Header not registered for template.
635	REJECTD	Template variable exceeded max length.
636	REJECTD	Error identifying template.
637	REJECTD	Invalid template ID.
638	REJECTD	Invalid SMS type.
639-649	REJECTD	Template reserved.
650	REJECTD	Preference not matched.
651-659	REJECTD	Preference reserved.
660	REJECTD	Consent failed.
661-669	REJECTD	Consent reserved.
670	REJECTD	Scrubbing failed.
671	REJECTD	DLT scrubbing timeout.
672	REJECTD	Invalid or missing mandatory TLV.
673	REJECTD	Invalid or missing TLV PE_ID.
674-699	REJECTD	Scrubbing reserved.
700	PRSBMIT	Promo submitted to operator.

Optional Parameters	Optional Tag value Decimal	Optional Tag value Hex
PE_ID	5120	1400
Template_ID	5121	1401
Telemarketer_ID (TM_ID)	5122	1402

DLT Error Code Details