Opinion ID: 785085
Heading Depth: 2
Heading Rank: 3

Heading: Headers

Text: 50 Multi-Tech also argues that the district court erred in its construction of the term headers in claim 1 of the '649 patent and claims 1, 2, 5, 7, and 13 of the '627 patent. Multi-Tech maintains that the term headers should be given its ordinary meaning of information structures that precede units of data, such as packets. Multi-Tech thus asserts that the headers attached to computer data packets need not identify packet type or packet length and that the headers attached to voice data packets need not identify whether the packets contain speech or silence. According to Multi-Tech, the district court improperly imported those additional limitations from the specification's preferred embodiments into the claims, despite the broader claim language. 51 Microsoft responds that the term headers has several ordinary meanings and that Multi-Tech's proposed definition is inconsistent with the specification's preferred embodiment and various dictionary definitions. Microsoft also argues that the specification requires both that the computer data packet headers identify packet type and packet length and that voice data packet headers indicate whether the packets contain speech or silence. 52 We agree with Multi-Tech that the district court's interpretation of the term headers was overly narrow. Claim 1 of the '649 patent refers to placing headers on the voice data packets as well as placing headers on the computer data packets. '649 patent, col. 47, ll. 5-13. Claims 1 and 7 of the '627 patent simply refer to voice data packets having headers, '627 patent, col. 46, ll. 47-49; id. at col. 47, l. 14, while claim 13 recites placing headers on outgoing voice data packets, id. at col. 48, l. 39. We therefore start from the presumption that the term headers carries its ordinary meaning of information structure[s] that precede[] and identif[y] the information that follows. Microsoft Computer Dictionary 215 (4th ed.1999). 53 Considering both the claim language and the specification, we next conclude that the claimed headers, at least in the '649 patent, must identify whether the packets are voice or computer data packets. 7 To begin with, the claim language of the '649 patent separately refers to placing headers on voice data packets and placing headers on computer data packets. Moreover, the specification states that [t]he voice data packet information ... uses a different header format [than does the computer data packet information] so the receiving site recognizes the difference between a data packet and a voice packet. '289 patent, col. 13, ll. 17-20. Such differentiation is necessary to enable the prioritization of voice data packets over computer data packets that, as discussed above, must occur when the two types of packets are multiplexed together. We therefore read the claim language, in light of the specification, as requiring that the headers of the '649 patent identify whether the following packets contain voice or computer data. 54 We further conclude, however, that the claimed headers need not identify the computer data packets' type and length or whether the voice data packets contain speech or silence. To be sure, the specification does disclose a preferred embodiment in which the computer data packets begin with an ID byte specifying the type and length of the packet, id. at col. 20, ll. 36-43 & tbls. 3-5, and the voice data packets have a sign byte specifying whether the packet contains silent sound or speech information, id. at col. 34, l. 64 to col. 35, l. 2 & tbl. 15. The district court determined that such additional limitations must be read into the claims because they are necessary [f]or the preferred embodiment to function as specified. Markman Order, slip op. at 37. 8 However, those statements are limited to descriptions of the packet protocol used in the preferred embodiments, see '289 patent, col. 18, l. 13; id. at col. 33, l. 61, and are merely illustrative of how the headers can be configured. We therefore conclude that the claimed headers need not identify the computer data packets' type and length or whether the voice data packets contain speech or silence.