svcVllType
1.3.6.1.4.1.6527.3.1.2.4.2.2.1.18
The value of the object svcVllType specifies, for a apipe,
fpipe or cpipe service, the type of pseudo-wire to be
signalled for the service. The default for this object
depends on the service type:
'atmSdu' for apipes, 'frDlci' for fpipes, satopE1 for
cpipes, and 'undef' for all other service types.