This attribute specifies whether tandem pass through is desired. If
tandemPassThrough is enabled, tandem pass through is used if
possible. If tandemPassThrough is disabled, tandem pass through is
not used under any circumstances. The actual state of tandem pass
through is indicated in Vsr Svs Framer tptStatus.
The negotiated tandem pass through is available in Vsr Svs Framer
negotiatedTandemPassThrough.
Tandem pass through is not supported on 1pDS1V and 1pE1V
cards, so tandemPassThrough is ignored on these cards.