Multimedia Messaging Service
MMS is still widely used for group messaging (iMessage fallback on non-Apple devices), marketing images, and vCards. Understanding MM7 (application-to-MMSC API) is needed when integrating with carrier MMS gateways.
What It Defines
MMS extends SMS to support multimedia content: images, audio, video, and formatted text. The OMA MMS spec defines the MM1 interface (UE to MMSC), MM4/MM7 inter-carrier and application interfaces, MIME-encapsulated message format, and WAP push delivery. Still used for group messaging fallback and marketing media.
Canonical (Normative)
Industry body that produces interoperable mobile service specifications. Published MMS, OMA DM (device management), LwM2M (Lightweight M2M), and push notification standards. OMA SpecWorks is the current name for the technical work.
Related Specs
SMS is how billions of people receive OTP codes, alerts, and notifications. Understanding PDU format, encoding (GSM-7 vs UCS-2), and concatenation is essential for any platform sending SMS at scale via Twilio, AWS SNS, or direct SMPP.
RCS is replacing SMS for brand messaging, OTP, and consumer engagement. Every major US/EU carrier now supports RCS Universal Profile. If you build SMS communications today, you need to understand RCS UP for 2025+ deployments.
3GP is the standard container for mobile-recorded video/voice messages, MMS media, and legacy carrier content. Shares ISO BMFF box structure with MP4 but restricted codec set.
The AMR file header is a minimal envelope pattern — one magic line then framed payloads. Required when parsing `.amr`/`.awb` attachments from carrier APIs or MMS gateways.
Telephony and messaging apps exchange contacts as `.vcf` files — parsed in MMS (MMS vCard attachments), QR contact cards, and SIP presence. TEL property formatting ties directly to E.164.
JPEG dominates photo storage and delivery. EXIF metadata (GPS, camera, orientation) lives in APP1 markers — relevant for privacy, image processing, and upload pipelines.
PNG is the default lossless image format on the web — screenshots, UI assets, icons with transparency, and OCR-friendly graphics. Chunk structure matters for metadata stripping and security review.