Advisory
July 2001
T8302 Internet Protocol Telephone Advanced RISC Machine
(ARM®) Ethernet QoS Using IEEE® 802.1q
Description
The Agere Systems, Inc. Voice over Internet Protocol (VoIP) Phone-On-A-Chip™ solution currently imple-
ments a quality of service (QoS) strategy that uses a proprietary voice packet prioritization scheme called
Ethernet Quality of Service using BlackBurst (EQuB). This scheme uses an algorithm (implemented in hard-
ware) to ensure that voice packets transmitted from the device are given the highest priority on their collision
domain.
The Phone-On-A-Chip solution will now become more standards based by implementing a QoS strategy that
incorporates a software-based IEEE 802.1q tagging protocol for outgoing Ethernet frames. This QoS imple-
mentation will utilize an IEEE 802.1q protocol stack from Wind River Systems® and will be integrated into the
VxWorks® board support package (BSP) for the T8302 as part of our standard software solution. Virtual local
area network (VLAN) tag insertion will be supported on a per-port, per-socket, and global basis.
Note: As a result of migrating to this software/standards-based priority scheme, Agere will no longer support
its current proprietary hardware-based EQuB scheme.
Customers using the Phone-On-A-Chip IP Solution Development Design Kit should be aware of this enhance-
ment and should structure their application software accordingly (to incorporate the features provided by the
IEEE 802.1q stack).
It is hoped that this migration will aid customers of Agere in implementing their own systemwide QoS mecha-
nism when designing their end product into an IP network.
Additional information may be obtained at the T8300 Phone-On-A-Chip website:
http://www.agere.com/phone_chip