Methods and apparatus for extending MAC control messages in EPON
One embodiment provides a media access control (MAC) module facilitating operations of an Ethernet passive optical network (EPON). The MAC module includes a frame formatter configured to generate a MAC control frame. The generated MAC control frame includes at least one of: an organizationally unique identifier (OUI) field, an QUI-specific operation code (opcode) field, and a number of fields associated with the QUI-specific opcode. Transmission of the MAC control frame facilitates realization of an EPON function based on the fields associated with the QUI-specific opcode.
1. An optical line terminal (OLT), comprising:
an OLT chip configured to facilitate data transfer between a carrier network and an optical networking unit (ONU); and
a Media Access Control (MAC) module, coupled to the OLT chip, configured to generate a MAC control frame, the MAC control frame comprising a timestamp indicative of a difference between a phase of an OLT clock and a phase of an ONU clock,
wherein the OLT chip is further configured to:
transmit a first data field within the MAC control frame indicative of a frequency of the OLT clock, and
transmit a second data field indicative of a time interval between transmission of the second data field and a subsequent OLT clock edge, and
wherein the ONU clock is synchronized to the OLT clock based on the timestamp, the first data field, and the second data field.
2. The OLT of claim 1 , wherein the MAC control frame further comprises:
a third data field indicative of a number of a plurality of queue sets allowed in a control message sent by the ONU; and
a fourth data field indicative of a threshold packet length corresponding to a queue set from among the plurality of queue sets sent in the control message.
3. The OLT of claim 2 , wherein the MAC control frame further comprises:
an organizationally unique identifier (OUI) field; and
an OUI-specific operation code (opcode) field,
wherein the third data field and the fourth data field are assigned to an OUI-specific opcode field value.
4. The OLT of claim 2 , wherein the MAC control frame is an extension of a multi-point control protocol (MPCP) MAC control frame.
5. The OLT of claim 2 , wherein the MAC module is further configured to:
generate a MAC GATE message including:
a grant-length data field indicative of a plurality of granted transmission times to the ONU corresponding to the plurality of queue sets; and
a grant-units data field indicative of a data granularity of the grant-length data field.
6. The OLT of claim 5 , wherein the grant-units data field is a value representative of a similar data granularity for the grant-length data field for the plurality of queue sets.
7. The OLT of claim 5 , wherein the grant-units data field is a value representative of different data granularities for the grant-length data field for the plurality of queue sets.
8. An optical line terminal (OLT), comprising:
an OLT chip configured to facilitate data transfer between a carrier network and an optical networking unit (ONU); and
a Media Access Control (MAC) module, coupled to the OLT chip, configured to:
generate a MAC control frame, the MAC control frame comprising:
a first data field indicative of a number of a plurality of queue sets allowed in a control message sent by the ONU, and
a second data field indicative of a threshold packet length corresponding to a queue set from among the plurality of queue sets sent in the control message, and
generate a MAC GATE message, the MAC GATE message comprising:
a grant-length data field indicative of a plurality of granted transmission times to the ONU corresponding to the plurality of queue sets; and
a grant-units data field indicative of a data granularity of the grant-length data field,
wherein the grant-length data field and the grant-units data field constitute a bit string, wherein a two most significant bits (MSBs) of the bit string are assigned to the grant-units data field, and wherein remaining bits of the bit string are assigned to the grant-length data field.
9. An optical networking unit (ONU), comprising:
an ONU chip configured to:
facilitate data transfer between the ONU and a networking enabled device,
receive, from the networking enabled device, a first data field within a Media Access Control (MAC) control frame indicative of a frequency of an optical line terminal (OLT) clock,
receive, from the networking enabled device, a second data field indicative of a time interval between transmission of the second data field and a subsequent OLT clock edge, and
synchronize an ONU clock to the OLT clock based on the timestamp, the first data field, and the second data field; and
a MAC module, coupled to the ONU chip, configured to generate:
a MAC control message including a plurality of queue sets, each queue set from among the plurality of queue sets having a first segment of data indicative of a queue length; and
a MAC control frame including a second segment of data indicative of a data granularity of the first data field.
10. The ONU of claim 9 , wherein the second segment of data is communicated between the ONU and an OLT via a report-units field in an extended control frame.
11. The ONU of claim 10 , wherein the second segment of data is representative of a similar data granularity for the first data field for the plurality of queue sets.
12. The ONU of claim 10 , wherein the second segment of data is representative of different data granularities for the first data field for the plurality of queue sets.
13. The ONU of claim 9 , wherein the second segment of data is communicated between the ONU and an OLT via a dedicated control message.
14. The ONU of claim 9 , wherein the MAC module is further configured to generate the MAC control frame to include the second segment of data being indicative of an increased data granularity for a smaller queue length than a larger queue length.
15. The ONU of claim 9 , wherein the MAC control frame further comprises:
an organizationally unique identifier (OUI) field; and
an OUI-specific operation code (opcode) field;
wherein the second data field is assigned to an OUI-specific opcode field value.
16. The ONU of claim 9 , wherein the MAC control frame is an extension of a multi-point control protocol (MPCP) REPORT.
17. In an Ethernet passive optical network (EPON), a method comprising:
transmitting, by an optical line terminal (OLT), a timestamp within a media access control (MAC) control frame indicative of a difference between a phase of an OLT clock and a phase of an optical networking unit (ONU) clock;
transmitting, by the OLT, a first data field within the MAC control frame indicative of a frequency of the OLT clock;
transmitting, by the OLT, a second data field indicative of a time interval between transmission of the second data field and a subsequent OLT clock edge; and
synchronizing, by an ONU, the ONU clock to the OLT clock based on the timestamp, the first data field, and the second data field.
18. The method of claim 17 , further comprising:
generating the MAC control frame to include an organizationally unique identifier (OUI) field and an OUI-specific operation code (opcode) field.
19. The method of claim 17 , further comprising:
assigning the timestamp, the first data field, and the second data field to an organizationally unique identifier (OUI)-specific operation code (opcode) field value.
20. The method of claim 17 , wherein the transmitting the timestamp, the first data field, and the second data field further comprise:
transmitting the timestamp, the first data field, and the second data field within the MAC control frame as an extension of a multi-point control protocol (MPCP) MAC frame.
21. The method of claim 17 , wherein the synchronizing comprises:
phase locking a phase of the ONU clock to a phase of the OLT clock; and
frequency synchronizing a frequency of the ONU clock to a frequency of the OLT clock.