MT92210 Zarlink Semiconductor, MT92210 Datasheet - Page 51

• Manufacturer Part Number: MT92210
• Description: 1023 Channel Voice Over ip (VoIP) Processor
• Manufacturer: Zarlink Semiconductor

Data Sheet
6.2
Before getting to the IP level, the MT92210 must parse through all of the link-layer information and headers
contained in the packet. The MT92210 can support packets whose link-layer information begins with an LLC
header (Classical IP over ATM, LANE v2), a PPP header (Packet over SONET, PPP over ATM), an Ethernet
header (Ethernet, LANE v1), an MPOA tag (MPOA over ATM), an MPLS label, an IP header or application data. It
then plows through the successive layers of link layer headers and network headers to extract its identification key
made up of a combination of fields such as source and destination addresses, UDP source and destination ports,
RTP SSRC, MPLS,/MPOA/ELAN-ID tags as available. The parser gets the very first protocol information from “1st
Header” in Packet Reassembly Structure, and is able to find out all following headers therefore determines the
packet type automatically.
Some IP headers can get special treatment from the packet parser. Specifically, the “next header” field found in
IPv6 (and that, in many cases, can also be used as the “protocol” field in IPv4) can force special treatment of the
packet, such as deleting it or routing it as a non-UDP packet. In a similar fashion, the “options” field found at the end
of the IPv4 header as well as the “options” found in the hop-by-hop options header and the destination options
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Packet Parsing
Figure 25 - Format of Initial Search Structure (Refer to Figure 19 for field descriptions)
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Zarlink Semiconductor Inc.
Next Profile
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Match Packet Count [31:0]
Match Byte Count [31:0]
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RUN
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RTD
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MT92210
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