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Cisco 891 using v.92 port for backup

My company uses Cisco 891's in replacement of the 1811 where we would have DBU used via an external modem and a triggered time of 3 minutes after a primary connection failure was identified.  In testing the 891 in a Layer 2 failure environment, it is within milliseconds that the v.92 port is engaging after the layer 2 failure.  Has anyone been able to get it to attempt at a more than millisecond rate?  Any help would be very beneficial. 

Redacted config from router:

ip sla 1

icmp-echo <%= probeIP1 %> source-interface GigabitEthernet0

timeout 5000

frequency 30

ip sla schedule 1 life forever start-time now

ip sla 2

icmp-echo <%= probeIP2 %> source-interface GigabitEthernet0

timeout 5000

frequency 30

ip sla schedule 2 life forever start-time now

!

track 100 ip sla 1 reachability

delay down 180 up 180

!

track 200 ip sla 2 reachability

delay down 180 up 180

!

track 300 list threshold weight

object 100

object 200

!

interface Async1

no ip address

ip virtual-reassembly

encapsulation ppp

ip tcp adjust-mss 1062

no ip route-cache

dialer in-band

dialer pool-member 2

async mode interactive

routing dynamic

!

interface Dialer2

bandwidth 56

ip address negotiated

ip virtual-reassembly

encapsulation ppp

dialer pool 2

dialer idle-timeout 60

dialer string <%= dbudial1 %>

dialer string <%= dbudial2 %>

dialer-group 2

no cdp enable

ppp authentication chap pap callin

ppp chap hostname <%= dbulogin %>.<%= dburealm %>

ppp chap password <%= dbupassword %>

ppp pap sent-username <%= dbulogin %>.<%= dburealm %> password <%= dbupassword %>

no cdp enable

!

ip route 0.0.0.0 0.0.0.0 <%= wangateway %> track 300

ip route 0.0.0.0 0.0.0.0 Dialer2 254

!

line 1

modem InOut

stopbits 1

speed 115200

line aux 0

exec-timeout 30 0

modem InOut

stopbits 1

Debugs from when Layer 2 failure initiated:

000416: Mar 14 12:53:18.903 PST: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0, changed state to down

000417: Mar 14 12:53:19.903 PST: %LINK-3-UPDOWN: Interface GigabitEthernet0, changed state to down

000418: Mar 14 12:53:41.607 PST: Di2 DDR: ip (s=186.0.0.0, d=0.128.0.40), 2 bytes, outgoing interesting (set by protocol)

000419: Mar 14 12:53:41.607 PST: As1 DDR: rotor dialout [best] least recent failure is also most recent failure

000420: Mar 14 12:53:41.607 PST: As1 DDR: rotor dialout [best] also has most recent failure

000421: Mar 14 12:53:41.607 PST: As1 DDR: rotor dialout [best]

000422: Mar 14 12:53:41.607 PST: As1 DDR: Dialing cause ip (s=186.0.0.0, d=0.128.0.40)

000423: Mar 14 12:53:41.607 PST: As1 DDR: Attempting to dial <%= dbudial1 %>

These configs are a mirror of the 1811 (minus the obvious SLA interface being an FE and not GE) and the 1811 would wait 3 minutes before dialup was engaged ... In a Layer 3 failure scenario on the 891 I can get the 3 minute wait period before it attempts to dial out. 

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