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Glossary

Terms and Definitions

A​

API (Application Programming Interface) Interface used to communicate with the message queue backend system.

Auto-Scroll Feature in the web UI Logs tab that automatically scrolls to show newest log entries.

B​

Backend The message queue system that the SMPP Gateway connects to for retrieving and storing messages.

Bind An SMPP connection between two systems. Can be transmitter, receiver, or transceiver.

Bind Type The type of SMPP session:

  • Transmitter: Send messages only
  • Receiver: Receive messages only
  • Transceiver: Send and receive messages

Bind Failure When an SMPP authentication attempt fails, usually due to incorrect credentials or IP restrictions.

C​

CIDR (Classless Inter-Domain Routing) Notation for specifying IP address ranges (e.g., 192.168.1.0/24 represents 256 IP addresses).

Client Bind An outbound SMPP connection where the gateway acts as an ESME connecting to an external SMSC (typically a carrier's SMPP server). In this mode, the gateway is the client.

Connection Status Current state of an SMPP bind:

  • Connected: Active and operational
  • Disconnected: Not connected
  • Reconnecting: Attempting to establish connection

Counter A metric that only increases (resets on service restart), used for totals like messages sent.

D​

Data Coding SMPP field specifying message character encoding (GSM-7, UCS-2, etc.).

Deliver_SM SMPP PDU sent by an SMSC (server) to deliver a message to a connected ESME (client). Used by server binds to push messages to connected partners.

Delivery Failure When a message cannot be delivered, indicated by an error response from the carrier.

Delivery Receipt (DLR) Confirmation from the carrier about message delivery status.

dest_smsc Field in message queue indicating which SMPP connection should handle the message.

Disconnection When an active SMPP connection is terminated, either intentionally or due to error.

E​

Enquire Link SMPP keepalive message sent periodically to verify connection is active.

ESM Class SMPP field indicating message type and features.

ESME (External Short Message Entity) In SMPP terminology, the client application that connects to an SMSC to send or receive messages. When the gateway operates in Client mode, it acts as an ESME connecting to carrier SMSCs. When it operates in Server mode, it accepts connections from external ESMEs.

Exponential Backoff Retry strategy where wait time doubles after each failure (1min, 2min, 4min, 8min...).

F​

Firewall Network security system that controls incoming and outgoing network traffic.

Frontend Registration Process by which the SMPP gateway registers itself with OmniMessage Core. A heartbeat is sent every 60 seconds to keep the registration alive. If the gateway stops, the registration expires after 90 seconds and OmniMessage stops routing messages to it.

G​

Gateway The SMPP Gateway application that bridges between message queue and mobile networks.

Gauge A metric that can increase or decrease, representing current value (e.g., connection status).

Grafana Popular visualization tool for displaying Prometheus metrics in dashboards.

GSM-7 Standard 7-bit character encoding for SMS, supporting up to 160 characters per message.

H​

HTTP/HTTPS Protocols used for web communication. HTTPS is encrypted version.

I​

IP Whitelist List of allowed IP addresses that can connect to the gateway (security feature).

ISDN (Integrated Services Digital Network) Numbering plan commonly used for telephone numbers.

J​

(No terms)

K​

Keepalive Periodic messages (enquire_link) sent to maintain connection and detect failures.

KPI (Key Performance Indicator) Measurable value indicating system performance (e.g., delivery success rate).

L​

Label In Prometheus, key-value pairs attached to metrics for identification (e.g., bind_name="vodafone_uk").

LiveView Phoenix framework technology used for real-time web UI updates.

M​

Message Queue Backend system that stores messages waiting to be sent or received.

Metrics Quantitative measurements of system performance, exposed in Prometheus format.

MO (Mobile Originated) Messages sent from mobile phones to the gateway (inbound).

MT (Mobile Terminated) Messages sent from the gateway to mobile phones (outbound).

MSISDN (Mobile Station International Subscriber Directory Number) Standard format for mobile phone numbers.

N​

NPI (Numbering Plan Indicator) SMPP field specifying the numbering scheme (e.g., ISDN).

O​

Outbound Messages flowing from gateway to mobile networks.

Inbound Messages flowing from mobile networks to gateway.

P​

PDU (Protocol Data Unit) Individual SMPP message packet (e.g., submit_sm, deliver_sm).

Prometheus Open-source monitoring system that collects and stores time-series metrics.

Q​

Queue List of messages waiting to be processed or sent.

Queue Check Frequency How often (in milliseconds) the gateway polls the backend for new messages.

Queue Worker Component that retrieves messages from queue and sends via SMPP.

R​

Rate Limiting Controlling message throughput to comply with carrier restrictions. See TPS.

Receiver SMPP bind type that only receives messages (deliver_sm).

Reconnect Re-establishing a disconnected SMPP connection.

Retry Attempting to send a failed message again, usually with exponential backoff.

S​

Sequence Number Unique numeric identifier assigned to each SMPP PDU within a session. Used to match requests with their responses (e.g., matching a submit_sm with its submit_sm_resp).

Server Bind Configuration that allows external ESMEs (clients) to connect to the gateway. In this mode, the gateway acts as an SMSC (server) accepting inbound connections from partner systems.

Session Active SMPP connection between two systems.

source_smsc Field in the message queue indicating which server bind should deliver the message to its connected clients via deliver_sm.

SMPP (Short Message Peer-to-Peer) Industry-standard protocol for exchanging SMS messages between systems.

SMSC (Short Message Service Center) In SMPP terminology, the server component that accepts connections from ESMEs (clients) and handles SMS message routing and delivery. When the gateway operates in Server mode, it acts as an SMSC accepting connections from external ESMEs.

SSL/TLS Encryption protocols for secure communication.

Submit_SM SMPP PDU for submitting a message for delivery.

Submit_SM_Resp SMPP response to submit_sm, indicating success or failure.

System ID Username used for SMPP authentication.

T​

Telemetry Automated collection and transmission of system metrics.

TON (Type of Number) SMPP field specifying number format (e.g., international, national).

TPS (Transactions Per Second) Rate limit for maximum messages per second through a connection.

Transceiver SMPP bind type that can both send and receive messages (most common).

Transmitter SMPP bind type that only sends messages (submit_sm).

Throughput Message processing rate, typically measured in messages per second.

U​

UCS-2 16-bit Unicode character encoding for SMS, supporting up to 70 characters per message.

Uptime Duration that a connection or service has been continuously operational.

V​

Validity Period Time limit for message delivery attempt before expiration.

W​

Web Dashboard Browser-based user interface for monitoring and managing the gateway.

Whitelist See IP Whitelist and Source Address Whitelist.

X​

(No terms)

Y​

(No terms)

Z​

(No terms)

Acronym Quick Reference​

AcronymFull Term
APIApplication Programming Interface
CIDRClassless Inter-Domain Routing
DLRDelivery Receipt
ESMEExternal Short Message Entity
GSMGlobal System for Mobile Communications
HTTPHypertext Transfer Protocol
HTTPSHypertext Transfer Protocol Secure
IPInternet Protocol
ISDNIntegrated Services Digital Network
KPIKey Performance Indicator
MOMobile Originated
MSISDNMobile Station International Subscriber Directory Number
MTMobile Terminated
NPINumbering Plan Indicator
PDUProtocol Data Unit
SMPPShort Message Peer-to-Peer
SMSCShort Message Service Center
SMSShort Message Service
SSLSecure Sockets Layer
TLSTransport Layer Security
TONType of Number
TPSTransactions Per Second
UCSUniversal Coded Character Set
UIUser Interface
URLUniform Resource Locator
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