Ken, nice to chat with you! Thoughts? Thoughts! Well I would recommend you to read the Solution Reference Network Design Guides: www.cisco.com/go/srnd Might be a lot of stuff at first, but at least it is good stuff! On top, what really also is important from a project management perspective when rolling out VoIP: "Cisco Undertakes the Largest IP Telephony Deployment in Industry History" http://www.cisco.com/web/about/ciscoitatwork/case_studies/ipcommunications_dl4.html Many very good ideas and gotchas, especially for "techies" tending to forget to ask users what they want ;-) Regards, Martin P.S.: Being an instructor I obviously also would recommend to attend Cisco VoIP related training classes, which cover many aspects in theory and hands-on labs. ... View more

Hi Ken, afaik yes. The point in todays networks is however not only TCP. VoIP and Video are more crucial as outages in the range of a second will benoticeable (though mostly tolerable), whereas 15 second breaks in a telephone conversation usually are unacceptable. Thus the goals today are more 1 sec. convergence time than 10 sec. Or generally speaking: your users and applications will define acceptable or unacceptable convergence times. TCP session timeouts are only one piece of the puzzle. Regards, Martin ... View more

Hi Ken, generally network convergence is composed of many components: 1) failure detection 2) propagation time of failure information 3) path recalculation timers All three of them can be the major component. As for 1): with static routing in place the time could even be infinity, if no link down event occurs. If "active testing" is involved, i.e. some keepalive mechanism, then the interval and dead timers determine the contribution to convergence. Today IGPs like OSPF or also spanning-tree (rstp) can be tuned to have hello/dead timers in the few second range (sometimes even subsecond). One should be careful though, as trying to convert a Toyota station waggon into a top fuel dragster by just fueling it with Nitro might break the thing ... ;-) In other words: there are limitations with respect to CPU load, memory and bandwidth, which need to be taken into account. As for 2): this depends on IGP or EGP update timers. Generally link-state protocolls are faster, BGP might be the slowest. There are also throtteling timers involved (to save the Toyota ;-) All the timers can usually be adjusted though to speed up the process. As for 3): There are also throtteling timers for path recalculation and the available CPU ressources are also of some importance. In addition the complexity of the recalculation is important. F.e. RIP will just insert an Update into the IP routing table whereas OSPF recalculates the topology in some cases. Final statement: the default timers are usually choosen conservatively, there is room for improovement in most cases. To lower convergence time in a complete network you need detailed knowledge on a protocoll and device feature level as well as on network specifics (like average CPU load in a router). Regards, Martin For further reading: Caveats in Testing Routing Protocol Convergence http://www.cisco.com/web/about/ac123/ac147/archived_issues/ipj_8-4/testing_routing.html High Availability White Papers http://www.cisco.com/en/US/products/ps6550/prod_white_papers_list.html ... View more

Hi, yes, this is the typical setup. make sure both routers are in the same VLAN and everything should go smoothly. Hope this helps! Regards, Martin ... View more

Hi, afaik you can not. There are no show or debug commands providing this info. Only the receiving router allows you to check AS path prepending. In an internet environment you can try to see your BGP routes on route servers (f.e. traceroute.org has a collection of links). Regards, Martin ... View more

Hi, afaik this was a "special" feature on 2900XL and 3500XL switches to connect routers and servers, but NOT switches or Hubs. Have a look at "Overlapping VLANs and Multi-VLAN Ports" http://www.cisco.com/en/US/docs/switches/lan/catalyst2900xl_3500xl/release12.0_5_wc5/swg/swvlan.html#wp1028684 You should not connect such a port to another switch. Basically per-VLAN spanning tree will not work properly and loops could result (assuming redundant topology). Hope this helps! Regards, Martin ... View more

Hi, There are some thoughts on your problem: First, what is your problem? "bandwidth 1000" assures a minimum bandwidth of 1 Mbps to your important traffic, IF there is more than 3 Mbps overall traffic. derived questions: a) Are you sure your ACL is sufficient to describe the application? b) Can your application achieve more than 500 kbps throughput? There might be limitations based on server ressources, client ressources, TCP session parameters (TCP throughput = window size/RTT), etc., i.e. not network related. c) Are you also applying QoS in the opposite direction on ALL involved devices (switches, router)? Besides that, your config looks good. Regards, Martin ... View more

Hi, have a look at IP Videoconferencing Solution Reference Network Design (SRND) http://www.cisco.com/application/pdf/en/us/guest/netsol/ns280/c649/ccmigration_09186a00800d67f6.pdf and also at Cisco AVVID Network Infrastructure IP Multicast Design (SRND) http://www.cisco.com/application/pdf/en/us/guest/tech/tk363/c1501/ccmigration_09186a008015e7cc.pdf If those guides are not helpful you need to be more specific about your desired result, topology and issues you are running into. Hope this helps! Please rate all posts. Regards, Martin ... View more

Hi, this can be a hardware issue - but we cannot answer it without knowing your hardware. Can you post the relevant info and also your rejected config command plus error message (if available). Regards, Martin ... View more

Hi, There are some possibilities for voip and data over tunnels. 1) IF the packets pre-tunnel are marked (DSCP, IP precedence) then the GRE headers will also get the same markings. You can then setup a policy on the physical interface towards the internet to prioritize voip. 2) You could use "qos pre-classify" on both routers - newer IOS required though afaik. http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_chapter09186a0080087f3c.html 3) use one tunnel and a nested policy. Why do you need two tunnels? regards, Martin ... View more

Hi, ICMP should not be a protocol prioritized like voip packets. Thus also the AP or intermediate equipment like switches could add to the ping delay in transmitting other packets first. On the AP it also depends on the QoS settings for best effort traffic (above or below background). So even if a phone is on call, ping does not give precise values, unless you use an extended ping and set the TOS value to 184 (ef). If you do so on the other hand, you could interfere with your voip packets and degrade voice quality in the worst case. Regards, Martin ... View more

Hi Bjornarsb, The output indicates, that the policy-map is applied to the physical interface. Nested policies are allowed there. So why do you assume the setup is not supported? The solution should in the end be the last case you mentioned. Regards, Martin ... View more

Hi, where exactly do you configure "qos pre-classify"? Can you post the relevant portion of the config? It should be placed inside the crypto-map, Tunnel interface or virtual template. If it is not placed there, then the physical interface (GE) only "sees" encrypted traffic and thus no telnet can be detected. Hope this helps! Regards, Martin ... View more