Passive Optical Networks

sublayer [9, Clause 57] is an optional Ethernet MAC sublayer (Fig. 2.29) which

not only can be built in EPON but also in other Ethernet devices. In fact, EPON

only consists of a subset of the objects manageable by the OAM sublayer. Most

of the EPON ASICs are built with the OAM sublayer which can be used for

managing OLT and ONU.

2.8 G-PON AND EPON COMPARISON

A high-level comparison of EPON and G-PON is given in Table 2.4. From a

technical viewpoint, one major difference between G-PON and EPON is the

support for TDM circuits. G-PON divides upstream and downstream signals

into 125-ms frames. Data frames are encapsulated using the GEM encapsulation

with ...