Everything worth knowing, nothing that isn't.
How MMSC differs from SMSC
An SMSC handles small (≤140-byte) text payloads over the signalling channel. An MMSC handles arbitrary media (typically up to 600 KB-1 MB) over the data channel using MM1/MM4/MM7 protocols. The recipient's handset receives a WAP push notification with a URL; the handset then fetches the actual media over HTTP from the MMSC. This makes MMS a hybrid signalling+data service.
Why MMS adoption is uneven
Three reasons. iPhone never supported A2P MMS well — it converts inbound MMS to a thumbnail with degraded resolution. Carrier transcoding varies wildly by operator (a 600 KB image may arrive as a 20 KB JPEG after Etisalat's MMSC compresses it). Pricing is 5-10x SMS per message globally with no standard wholesale framework. For most A2P use cases, RCS or WhatsApp is the right channel for media; MMS makes sense for US-domestic short-code campaigns where MMS engagement rates are 2-4x SMS.
When MMS is the right choice
Two cases. US-based short-code campaigns where the operator MMS toll-free pricing is favourable and the audience is on iOS+Android. Verification flows that include an image of an ID document or a signed receipt. For these BroadNet exposes /products/mms with a unified API that handles per-operator transcoding constraints automatically.
Lifespan
MMS is in slow decline globally. New deployments should default to RCS for Android-heavy markets, WhatsApp for emerging markets, and iMessage Business for iOS-heavy ones — each replaces MMS with better media handling and richer interaction. MMSC remains in operator networks because removing it breaks the 5% of subscribers who still rely on MMS for cross-network media.