Hello everyone!
Basic Concepts
Service Multiplexing
GEM ports and T-CONTs divide a PON network into virtual connections for service multiplexing.
GEM Port
A GPON encapsulation mode (GEM) port is a virtual service channel that carries a service flow between the OLT and an ONU in a 10G GPON system. The GEM port is similar to the virtual connection (identified by VPI/VCI) in asynchronous transfer mode (ATM). VPI is the acronym for virtual path identifier and VCI is the acronym for virtual channel identifier.
Each GEM port is identified by a unique XGEM port ID.
The XGEM port ID is globally allocated according to the 10G GPON port by the OLT.
A GEM port can carry one or more types of services.
T-CONT
A transmission container (T-CONT) is the basic control unit of upstream service flows in a 10G GPON system and is also the unit for carrying service flows in the upstream direction. All the GEM ports are mapped to T-CONTs, and the OLT uses dynamic bandwidth allocation (DBA) to schedule upstream transmission.
A T-CONT can carry one or more GEM ports according to user configurations.
A T-CONT is identified uniquely by Alloc-ID.
The Alloc-ID is allocated according to the 10G GPON port by the OLT.
An ONU supports multiple T-CONTs configured for various service types.
Thanks.
