Sprint LTE NIM Experience

[kennytaylor661]

I have been doing some testing with the NIM-4G-LTE-ST (Sprint) NIM module.  Using the n.ispsn APN, the module connects and passes traffic for 3-5 minutes.  It then drops with a message indicating that the router has lost communication with the module and attempts to power cycle the module.  Running debug commands, including "debug cellular x/x/x message callcontrol" give no indication that a decision was made to drop the call.  I have verified the same behavior on two other NIM-4G-LTE-ST modules and two different model routers (4431 and 4320).

Have any of you seen similar issues with the Sprint NIMs?

Some of the config I'm using:

enable# cell 0/2/0 lte profile create 1 n.ispsn none ipv4v6

controller Cellular 0/2/0
    lte sim data-profile 1 attach-profile 1

interface Cellular 0/2/0

    ip address negotiated
    ipv6 address autoconfig

    dialer in-band

    dialer idle-timeout 0

    dialer-group 1

[Georg Pauwen]

Hello,

can you post the output of 'sh ver' from your router, as well as the output of 'show cellular 0/2/0 all' ?

[kennytaylor661]

Show command outputs attached.  Looks like we're running 15.5(3)S4b.  I also attached a copy of the debug output showing where it connects successfully, drops, and the router complains of losing communication with the module.  TAC actually send three replacement NIMs in response to my RMA request, and all three show the same behavior.

The attached "show cell 0/2/0 all" is taken after the initial call disconnects and the module no longer passes traffic.

[kennytaylor661]

Attaching the "show version" output..

[kennytaylor661]

Attaching the debug trace..

[kennytaylor661 · Accepted solution]

I realized this morning that I've been testing this with the same SIM card.  Different routers, different NIM modules, but the same SIM card.  Short answer is the SIM card comes up as invalid.  Testing again with the SIM from my personal hotspot, it stayed connected as expected.

The behavior is interesting, though, and I wanted to share it..  The LTE NIM module connects and passes traffic for approximately 3 minutes.  During this time, the downstream rate appears to be limited to 0.5 mbit.  After approximately 3 minutes, the cellular device is disconnected and dropped down from LTE to 3G.  It appears the device gets deauthenticated from the LTE network at this point.  Once this happens, the device is unable to reconnect to the LTE network.  The device pulls a new IP address on the 3G network but is isolated on the carrier side and does not pass traffic.

Thank you to everyone who looked over this post and gave it some thought!