Specifications

Watson 5 Ethernet
Operating Manual
W5-Ethernet-Manual.doc
Version 2.0-01
3-18 Revision: 2006-04-27
3.3.3 Mixed mode operation
The Watson 5 Ethernet tabletop modems are interoperable with other TDM-based Watson 5 mo-
dems:
Watson 5
Ethernet NTU
Watson 5
E1 LTU
DSL
1pair or 2 pairs
Ethernet
10/100baseT
Ethernet
10/100baseT
Watson 5
E1 LTU
DSL
1pair
2 pairs
E1 Transport Network
eg SDH
E1
E1
Watson 5
Regenerator
(Optional)
Watson 5
Ethernet NTU
Remote
Powering
Remote
Powering
Figure 3-13: Mixed mode operation
One pair and two pair links are supported in mixed mode operation. The maximum throughput is
2.048 Mbps (32 timeslots) in E1 mixed mode operation and 4.6 Mbps (72 timeslots) in nx64 mixed
mode operation. In mixed mode operation the Watson 5 Ethernet NTU can be powered from the
LTU and the Watson 5 Regenerator is supported.
Note:
In mixed mode operation Firmware Version 2.0 or higher is required on the LTUs.
3.3.4 Cisco HDLC
The Watson 5 Ethernet tabletop modem supports the "Cisco HDLC" formatting described in RFC
1547 with 16-bit FCS and bit-stuffed framing. In this mode an HDLC address and control field are
inserted in the frame:
DA SA
TCI ML/TL/T
DATA
CRC-16
DA SA
TCI
ML/T DATA
0x000xFF
Transmitted on DSL with
HDLCTAG OFF
Transmitted on DSL
with HDLCTAG ON
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
CRC Cyclic redundancy check sequence
0x65 0x58
Cisco HDLC
CRC-160x7E 0x7E
0x7E
0x7E
L/T
Figure 3-14: Cisco HDLC