[c-nsp] xconnect on subinterfaces c1841 possible?

[Christopher Hunt]

Hello all,
    I'm having some trouble getting xconnects to work on
subinterfaces.  I have two back-to-back c1841s with a T1 between them,
both running c1841-advipservicesk9-mz.124-12. The following config,
which uses two untagged ethernet ports works fine:

##working config##
ip cef
l2tp-class l2class
!
pseudowire-class pwire-DATA
 encapsulation l2tpv3
 protocol l2tpv3 l2class
 ip local interface Loopback0
!
pseudowire-class pwire-VOICE
 encapsulation l2tpv3
 protocol l2tpv3 l2class
 ip local interface Loopback0
!
interface Loopback0
 ip address x.x.199.5 255.255.255.255
!
interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
 no cdp enable
 xconnect x.x.199.6 100 pw-class pwire-VOICE
!
interface FastEthernet0/1
 no ip address
 duplex auto
 speed auto
 no cdp enable
 xconnect x.x.199.6 101 pw-class pwire-DATA
!
interface Serial0/0/0
 ip address x.x.199.1 255.255.255.252
 no fair-queue
 service-module t1 clock source internal
!
ip route x.x.199.6 255.255.255.255 x.x.199.2

But when I modify the config to put the xconnects on dot1q
subinterfaces, the l2tpv3 tunnels don't come up:
## broken config##
!
interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
 no cdp enable
!
interface FastEthernet0/0.10
 encapsulation dot1Q 10
 no cdp enable
 xconnect x.x.199.6 100 pw-class pwire-VOICE
!
interface FastEthernet0/0.20
 encapsulation dot1Q 20
 no cdp enable
 xconnect x.x.199.6 101 pw-class pwire-DATA



Any ideas?  Is xconnect on a subinterface a special feature which
isn't supported by this IOS?  TIA,

-Chris