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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: VoIP over IPsec
Using hardware encryption with the qos pre-classify feature, I imagine that jitter will no longer be an issue - (that is, the jitter you mention previously is introduced by the lack of prioritization into the encryption queue). Or am I missing something? C. -----Original Message----- From: Stephen Sprunk [mailto:[email protected]] Sent: Monday, February 17, 2003 2:24 AM To: Charles Youse Cc: [email protected] Subject: Re: VoIP over IPsec Thus spake "Charles Youse" <[email protected]> > In order to cut costs in our telecom budget I'm toying with the idea > of replacing a lot of our inter-office leased lines with VPN > connections over the public Internet. [...] > Assume for the moment that latency and bandwidth are not an issue; > e.g., any two points that will be exchanging voice data will both have > transit from the same provider with an aggressive SLA. Latency, bandwidth, and packet loss are moot. Jitter is VoIP's enemy. > Does anyone have any experience running VoIP over such tunnels? > Is there a technical reason why this solution is not feasible? Are > Cisco routers not happy doing VoIP/IPsec/GRE in concert? IPsec itself will not cause you problems; there's no theoretical conflict. Unfortunately, IOS can introduce jitter when encrypting packets. To mitigate this, you can apply QOS, with a strict priotiy queue for the VoIP packets and the "qos pre-classify" feature. Your mileage will vary depending on the CPU power of the router, the traffic levels, and whether you're using hardware encryption. S Stephen Sprunk "God does not play dice." --Albert Einstein CCIE #3723 "God is an inveterate gambler, and He throws the K5SSS dice at every possible opportunity." --Stephen Hawking
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