[c-nsp] Cisco 7204 Ethernet LMI Question

[florinb at teksavvy.com]

Hi, 
I would like to ask your opinion on an issue I see in a configuration where a 7204 acts as a CE and it is running Ethernet LMI on an FastE interface: 

interface FastEthernet2/0
no ip address
logging event subif-link-status
duplex full
no keepalive
ethernet lmi interface
ethernet lmi t391 10
ethernet lmi n393 4
!
interface FastEthernet2/0.10
encapsulation dot1Q 10
ip address 10.0.11.12 255.255.255.0

As soon as the PE is sending an Ethernet LMI Status Full Status message with one EVC MAP entry indicating that EVC10 (mapped to VLAN 10 )is new and active in the MEN, the line protocol on interface Fast 2/0 changes status to down, the subinterface Fast 2/0.10 stays up (because LMI indicated the EVC associated to VLAN 10 is active). 
c7204#show int fast 2/0
FastEthernet2/0 is up, line protocol is down
Hardware is AmdFE, address is 0005.dd6e.9038 (bia 0005.dd6e.9038)
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set
Keepalive not set
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:12, output 00:00:04, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/40/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
842 packets input, 62128 bytes
Received 0 broadcasts, 0 runts, 0 giants, 1 throttles
1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
17244 packets output, 1683765 bytes, 0 underruns
0 output errors, 0 collisions, 35 interface resets
57 unknown protocol drops
57 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

My take is the line protocol status on interface fast 2/0 changes to down because there was no indication from PE of an active EVC associated with VLAN 1 (native VLAN the system associates by default with interface fast 2/0). 
At this point the interface Fast 2/0 keeps sending Ethernet LMI PDUs (as expected by LMI protocol) but it does not accept any Ethernet LMI PDUs from PE ( Ethernet LMI PDUs are untagged ). 
If the PE includes the VLAN 1 in the CE-VLAN map it sends (or if I set the VLAN 10 as native on CE ) the Ethernet LMI PDUs exchange will be successful. 

I wonder if I miss something in CE configuration as it looks unusual to me the Ethernet LMI has to "enable" the data path it will use to send owns PDUs. 
Please let me know your opinion. 
Thanks, 
Florin