I have a C891FW-E-K9 ISR with ios c800-universalk9-mz.SPA.154-3.M-2. From what I can gather, the memory requirements for that image is 512MB but from "show version" my router seems to only have 384MB which could be the reason why it runs out of memory sometimes.
I am wondering if it's possible to upgrade the memory of the router and if possible, which module would be compatible. When I look for data sheets I find this one: http://www.cisco.com/c/en/us/products/collateral/routers/800-series-routers/data_sheet_c78-519930.html
As far as I can understand the C891FW is the same as C891F but with wireless and the data sheet states that default DRAM is 512MB and upgradeable to 1024MB with FL-8XX-512U1GB.
Why does show version tell me 384MB of DRAM when Data Sheets says 512MB? and is it possible to upgrade RAM of this model?
Thanks in advance!