# Edge Sync Services vs Transmission History **URL:** \ **Category:** Ignition\ **Created:** [August 3, 2022, 6:22pm UTC](https://forum.inductiveautomation.com/t/edge-sync-services-vs-transmission-history/62645 "2022-08-03T18:22:39Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![jacob.ramirez](https://avatars.discourse-cdn.com/v4/letter/j/9dc877/32.png) [@jacob.ramirez](https://forum.inductiveautomation.com/u/jacob.ramirez)\ **Post date:** [August 3, 2022, 6:22pm UTC](https://forum.inductiveautomation.com/t/edge-sync-services-vs-transmission-history/62645/1 "2022-08-03T18:22:39Z")
I’m curious if anyone can shed some advice on the two services mentioned in the title of this post. I am using the MQTT transmission module and enabled the history there. As well as the steps in this post [post](https://forum.inductiveautomation.com/t/feature-allow-reference-tags-to-receive-backfill-data-from-sources-like-mqtt-tags/48261/6) about “Allow Backfill data”. Now I’m curious if I’m only concerned about missed data when the Edge site loses connection for some period of time, will the History on the Transmission module be fine for that? Or if its a long period of time, I would the Ede Sync Service license? ---
**Author:** ![michael.flagler](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/michael.flagler/32/26272_2.png) [@michael.flagler](https://forum.inductiveautomation.com/u/michael.flagler)\ **Post date:** [August 22, 2022, 11:34pm UTC](https://forum.inductiveautomation.com/t/edge-sync-services-vs-transmission-history/62645/2 "2022-08-22T23:34:54Z")
The store and forward on the transmission module has configurable limits to prevent filling storage/RAM, and it will backfill, but if you reach your limit, older data will start getting dropped. I haven’t used the Edge Sync services, but I’m assuming it has some similar limit in it, although it could be based on available storage vs transmission is limited by number of records stored.