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SoftPhone only on PC connected to Cat 6000?

Unanswered Question
Dec 15th, 2000
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I found this article on CCO which seems to say that a PC running SoftPhone needs to be connected to a Cat 6000 with PFC. If this correct? Can the PC be connected to a 3524, for example, in the closet which in turn is connected to a 6000 with PFC?


http://www.cisco.com/univercd/cc/td/doc/product/voice/ip_tele/avvidqos/qosphone.htm#xtocid226318


Installing SoftPhone

Some enterprises are deploying IP telephony using the Cisco SoftPhone application. In addition, there are many more enterprises that wish to evaluate the viability of using PC-based VoIP applications. Many PC network interface cards (NICs) do not currently set 802.1P CoS bits for Layer 2 classification. Even if the PCs did set Layer 2 frame markings, the vast majority of enterprise administrators would resist "trusting" a user's PC. Because of these factors, Cisco SoftPhone currently classifies voice packets only at the Layer 3 IP header. In fact, all voice bearer packets originating from the Cisco SoftPhone application are marked with an IP Precedence value of 5. Of course, this marking requires a wiring closet Ethernet switch that is Layer 3 enabled, with multiple queues, to correctly queue these voice packets. Currently, this limits Cisco SoftPhone designs to PCs connected to Catalyst 6000 switches with a Policy Feature Card (PFC) installed.



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snoop-09 Sun, 12/17/2000 - 10:54
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You can connect the SoftPhone to anything. All they are saying is that to improve the Quality of Service (QoS), it would be best if only Layer 3 enabled switches were to "route" the voice traffic within the LAN. Layer 2 only switches cannot give a priority to voice traffic, because the only distinguishing factor is the Precedence bit in the IP (layer 3) header.

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