Seperate Voicemail server and mwi

I am having difficulty getting the mwi light to light up on my phones. here is a basic configuration:

voicemail server - IAX2 connection to MAIN voip server, SIP connection to router running Asterisk with phones attached
Main server: main incoming server for most calls, or calls are routed here from secondary server with other external trunks
router - runs asterisk with iax connection to main server so calls can be routed. I setup a sip connection back to the voicemail server

voicemail and main server is 11.6 certified
router running 11.2 certified

Sip conf from voicemail (with various settings I have tried)
[general]
allowoverlap=no
bindport=5060
bindaddr=0.0.0.0
srvlookup=no
disallow=all
allow=g729
subscribecontext=from-sip
nat=force_rport,comedia

messagewaiting
type=peer
subscribecontext=fromiax
context=fromiax
qualify=yes

9993
mailbox=9993@default
defaultuser=9993
secret=1234
host=XX.XX.XX.XX

sip.conf from router:
[general]
context=incoming
allowoverlap=no
bindport=5060
bindaddr=XX.XX.XX.XX
srvlookup=no
disallow=all
allow=g729
subscribecontext=from-sip
session-timers=accept
session-expires=43200
register => 9993:1234@YY.YY.YY.YY/9993
mwi => 9993:1234@YY.YY.YY.YY/9993

;Sip trunk to voicemail server
[atlvm]
type=friend
secret=SomESecReT
context=voicemail-inc
disallow=all
allow=g729
qualify=yes
host=YY.YY.YY.YY

voicemail config on voicemail server:
[general]
maxsilence=0
format=g729

[default]
9993 => 1234,hi9993

I am sure I have too many things wrong at this point, but finding it difficult to find any real information on this. I sure could use some clarity.

What I would like to happen is that the router talks directly to voicemail server via IAX to leave the message (I guess this could be SIP, does it matter?), and I have this part working.
Then the voicemail server connects to the router via SIP to light the MWI. All the mailboxes for the router are the same (I have soft links from all the extensions in the router voicemail directory 999301 > 9993, 999302 > 9993, etc. )

At this point I am so confused I am not sure where to turn, hoping someone here can help me make some sense of this, having a real hard time finding anything on this beyond: asteriskdocs.org/en/3rd_Edit … 93070.html and I am not certain how up to date this is.

Thanks in advanced for any help.
Cheers!