Specifications

Watson-SHDSL-Router-Manual.doc
Version 1.1-07
Watson SHDSL Router
Operating Manual
Revision: 2012-02-15
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3-13
DA SA
TCI ML/TL/T
DATA
Transmitted on DSL
stripped off before transmission over DSL
PRE Preamble
SFD Start-of-frame Delimiter
DA Destination address
SA Source address
L/T Length or type indicator = 802.1 QTagType
TCI Tag control information
ML/T MAC client length/type
DATA MAC client data
PAD Padding bytes
CRC Cyclic redundancy check sequence
generated before transmission over DSL
CRC-160x7E 0x7E
HDLC Framing (Flag character)
DA SA TCI
ML/T
L/T
DATA
MAC frame format with
IEEE 802.1p/q VLAN tags
CRC-32SFDPRE PAD
Figure 3-3: Ethernet over DSL with HDLC encapsulation
The EFM 64/65b framing mode is used when two Watson SHDSL routers are
connected point-to-point together or for connecting a Watson SHDSL router to
another IEEE 802.3ah EFM compliant device.
Figure 3-4: EFM fragmentation and framing