Release Notes

BCM 3.6 and SRG 1.0 Wireless IP Telephony Patch
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replaces the SVP protocol number, 0x77, with the UDP number, 0x11. For
packets going from the network to the handset the protocol number is changed
from 0x11 to 0x77.
SVP is required for QoS because the current IEEE 802.11b wireless LAN
standard provides no mechanism for differentiating audio packets from data
packets. This standard is undergoing revision to version 802.11e to provide
functionality similar to SVP in an industry standard thus ensuring high-quality
voice in a mixed client environment.
Because packets which traverse the network between the handset and the 2245 are
not standard IP packets, i.e. they use a non-standard protocol number, there can
not be any layer 3 routing in the path. Therefore the handsets and 2245 server
must be in the same logical subnet.
• The RTP packets between the handset and the 2245 server always contain 30
msec worth of voice no matter what has been configured on the call server. The
2245 repackage the RTP packets to conform to the size which has been
configured in the call server. This provides more efficient use of the available RF
bandwidth at the expense of slightly increased jitter and latency.
• The 2245 is configured with a maximum allowable number of simultaneous
media streams on a single access point. The 2245 keeps track of the number of
media streams on each AP and blocks calls to / from a set which would exceed the
configured capacity.
• There is also a keep alive packet exchange which runs between the handset and
the 2245 every 30 seconds. If the handsets detects the 2245 is unreachable it will
reset and attempt to re-establish a connection with the Master 2245 server.
MAC Address Based QoS
The existing Nortel wireless Access Points, the 2220 and 2221, are not SVP compliant.
However beginning with firmware release 1.3 they support MAC address based filtering.
The APs can be configured such that packets that are destined for specific MAC
addresses are given priority on the radio link. The MAC address for the family of 2210
and 2211 phones have been pre-configured in the APs.
End to End QoS
The 2210/11 does not support any Layer 2 or Layer 3 QoS mechanisms such as 802.1p or
DiffServ. Any UNIStim messages which are sent to the handset to adjust the Layer 2 or
Layer 3 QoS settings are ignored. In addition, the 2245 server does not support any Layer
2 or Layer 3 QoS mechanisms.
4. Documentation
The following documents will be introduced with the release of the Wireless IP Handsets
2210 and 2211. They will be posted for download from the Helmsman website for the