Schmid SHDSL - DSL; Linerates and DSL sync rates

Watson-SHDSL-Router-Manual.doc
Version 1.0-03
Watson SHDSL Router
Operating Manual
dium and low. By default, values six and seven are mapped to high priority, which may be assigned
to network-critical traffic. Values four and five are mapped to medium priority, which may be applied
to delay-sensitive applications, such as interactive video and voice. Values three to zero are
mapped to low priority, which may range from controlled-load applications down to "loss eligible"
traffic. The zero value is normally used for best-effort traffic. It is the default value for traffic with un-
assigned priority.
3.4.6 DSCP Remark According to 802.1p CoS
When creating a VLAN interface over a LAN connection, it is possible to determine the IP header's
Differentiated Services Code Point (DSCP) priority value according to the VLAN header's 802.1p
Class of Service (CoS) tag. The DSCP value can then be used for Quality of Service (QoS) traffic
prioritization.
3.4.7 Class Statistics
Watson SHDSL router provides accurate, real-time information on the traffic moving through the de-
fined device classes. For example, the amount of packets sent, dropped or delayed, are just a few
of the parameters that can be monitored per each shaping class.
3.5 DSL
3.5.1 Linerates and DSL sync rates
Watson SHDSL router supports SHDSL as specified in ETSI TS 101 524 and ITU-T G.991.2. The
linecode used is TC-PAM 16, the maximum linerate rate per pair is 2'306 kbit/s (36 timeslots with 64
kbit/s each).
Watson SHDSL can be configured for the 2004 revision of ETSI TS 101 524, also known as eSDSL
(ETSI) or G.SHDSL.bis (ITU-T). G.SHDSL.bis allows for higher symbol rates and a 32-level line-
code (TC-PAM 32). The maximum number of timeslots per pair in G.SHDSL.bis is 89, the maximum
linerate rate per pair is 5'696 kbit/s.
There is some overlap between the linerates attainable in G.SHDSL and G.SHDSL.bis, cf.
:
Figure
3-2
Figure 3-2: G.SHDSL and G.SHDSL.bis linerates
G.SHDSL, ETSI TS 101 524 TC-PAM 16
-TC-PAM 16
G.SHDSL.bis, ETSI TS 101 524 (2004)
-TC-PAM 32
Linerate
kBps
5'000 5'000 1'0001'000 2'0002'000 3'0003'000 4'0004'000 6'0006'000
This means that for certain linerates either TC-PAM 16 or TC-PAM 32 can be configured in the mo-
dem. TC-PAM 16 has better DSL performance than TC-PAM 32. However with linerates rates
higher than 2.3 Mbps (36 timeslots) and TC-PAM 16 the symbol rate over the DSL becomes higher
than what was specified in the original version of TS 101 524. Higher symbol rates mean wider
Revision: 2007-05-24 3-9