Douglas Garstang
2006-Mar-16 08:20 UTC
[Asterisk-Users] Feedback from VON expo! Info on * HA andPolycomphone!!
Great Email. I'm going to respond to some of the points. "Q: What are the plans for HA? A: With a configuration using DNS-SRV and DUNDi, you can create a pretty resiliant setup now." That's BS. Last time I checked, Asterisk's support of SRV was to only grab the first SRV entry. Period. If it doesn't try any more SRV hosts after the first fails, just exactly how is that redundant? "Q: What the deal with the limit on the number of people you can monitor for presence? A: There is no limit in the phone. This is an Asterisk limitation." That's BS too. I have an email thread from a Polycom employee where they recognised it was a Polycom issue and was told they might have an newer version of the SIP software out to address this by summer. Still can't fathom why this takes months to fix, but anyway... "Q: Whats the best way to program the phone to handle failover? A: Use a DNS-SRV address for the primary server. When the phone queries the DNS server, it will receive a list of all the possible servers " This is broken to some degree. When the phone refreshes it's cache, and grabs the list of SRV servers again, it will continue to use them in the same manner until it refreshes it's cache again, or there is a failure, even when all SRV hosts have the same priority and weight. It should round robin in this case. And in regards to Asterisk HA, and approach #2. If you have your SER boxes use the send() command to stateless forward registrations, you can send registrations from the phones to ALL your Asterisk systems so that every Asterisk box knows about every phone, and every Asterisk box can route calls from/to any phone. Doug -----Original Message----- From: Jim Houser [mailto:jhouser@trustamerifirst.com] Sent: Thursday, March 16, 2006 7:50 AM To: 'Asterisk Users Mailing List - Non-Commercial Discussion' Subject: RE: [Asterisk-Users] Feedback from VON expo! Info on * HA andPolycomphone!! Gabe. Who was the call-center program from? Thanks, Jim -----Original Message----- From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of Gabriel Afana Sent: Thursday, March 16, 2006 2:38 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: [Asterisk-Users] Feedback from VON expo! Info on * HA and Polycomphone!! Hey group, I just got back from the VON expo. It was insane....there were so many companies there. The #1 thing ***EVERY*** company focused on was "convergance" - getting all your communication devices to intergrate with eachother. There were some nifty products out there that did some cool stuff :-) Of course Digium/Asterisk was there and I had a list of questions for them. I went by several times asking more and more questions...by the last visit, these guys were running from me because I was driving them nuts :-) Here are all the questions I asked them (this is not word for word...just a summary): Q: What are the plans for HA? A: With a configuration using DNS-SRV and DUNDi, you can create a pretty resiliant setup now. Q: What about failover without losing a call A: IBM has been able to make asterisk do this. However, at this time we are not working on any solution to offer this as part of the program. Q: Do you plan on offering support for other distros for Asterisk Business Edition? A: [uncertain answer] Not really sure...maybe SuSE...not sure Q: When is asterisk going to fully support video? A: Asterisk can complety support video using H.261, H.263 and we recently added support for H.264 Q: What do you recommend as the best solution for HA? I got two different answers for this from two different people there. Both made good sense and are basically what everyone is doing now. Here both approaces are in a nut-shell: Approach 1 (seemed to be the preferred method): Use DNS-SRV lookups for all registrations. This will distribute the calls among the * servers. Next, you configure your servers using regexten and DUNDi. You use regexten to dynamically create the "exten => 1234,1,NoOp" when a phone registers with that server. Then when a call comes in, you use DUNDi to try to complete the call locally. If the phone is not registered to that server, then do a DUNDi lookup to find the server that the phone is registered to and then pass the call over IAX to that server to take it to the phone. Of course the phones will need to have a short registration expiration so they update frequently because if the server they are registered to crashes, until it re-registered, no server can access it. But by doing this, the phone will re-register to another server and then the next DUNDi lookup will then go to this new server. I asked about the load of having many phones registering frequently and he said it is no big deal at all. He also said it was very important to make sure cache is disabled in DUNDi!!! Each call that is made should result in a new query. This will ensure the calls are not getting old cached info which may no longer be accurate. Approach 2: Use a SER box to handle all registrations. The SER box will take care of distributing the load between the * boxes. You do not use DUNDi or regexten in this case. Just let each * box function on its own. If one of the servers fails, SER will not use it to terminate calls. Sinces the phones are registering to SER, and all incoming calls will be routed to SER, you do not need to worry much about the * boxes. You just need to make sure you have your SER boxes in a cluster to fail-over in the event of failure. Overall theme of the Asterisk stand: selling third-party products. In the there section, Digium had 10 seperate vendors that have teamed with them to sell special programs/products/services that intergrate with Asterisk. One was a call-center program, another was a resellers package, another delt with firewalls and NAT, another for voice recognition, another was Intel (that has partnered with Digium to offer drivers in the ABE for the intel cards), another was some email, fax, chat, presence, etc. kind of box that sits in front of * to combine all these services....and some others I dont remember. It felt like I was walking into an infomercial! I also spoke with Polycom guys a great deal and asked many questions: Q: Do you plan on offering 10/100/1000 ports on the phones? A: Yes, in the near future Q: Do you plan on offering a standard phone jack for failover purposes? A: No, we have no talks of this. However, I will take this idea to the production development team. Q: What is the "services" button ever used for? A: This is only operable in the 601 and is used to launch the XML browser. We have partned with many companies to offer you sports, weather, stock, movie ticket info...etc that can be fed directly to the phones screen. Q: What the deal with the limit on the number of people you can monitor for presence? A: There is no limit in the phone. This is an Asterisk limitation. Q: How can you get the name of the person you are calling to appear on the phone instead of their extension? (they had a demo of their phones there and they were doing this!!!) A: You enter the information into the phone book directly via the XML script loaded from the bootserver. Since all the phones will use the same bootserver to fetch the XML script, they will all have each others extension numbers and associated names. When you call another extension, their name will then appear. Q: When the phone is unable to make a call through the primary server and it redirects to the secondary server, does it just make the call or does it also register with the secondary server? A: No, it will not register with the secondary server automatically. This is done on purpose to help reduce unneccessary registrations. Q: Whats the best way to program the phone to handle failover? A: Use a DNS-SRV address for the primary server. When the phone queries the DNS server, it will receive a list of all the possible servers to send the call to. The phone will try to register to the first server; if this fails, it will go to the second server...and so on through the list until it can register. Once it is registered with a server, if that server fails (or the phone is unable to reach that exact server for some reason), the phone will *not* go to the secondary server!!! The results of the DNS lookup are saved on the phone so if the call doesn't go through to the server its registered with, it will recall the saved list of servers available and go through that list. Because of this, there is no need to go to the secondary server section since it will simply loop through all the servers it received during the DNS-SRV lookup. I am sure there were many things I left out or forgot to say. If I remember, I'll be sure to post them. - Gabe _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users This e-mail and any attachments may contain confidential and privileged information. If you are not the intended recipient, please notify the sender, or postmaster@trustamerifirst.com, immediately by return e-mail and destroy any copies. Any dissemination or use of this information by a person other than the intended recipient is unauthorized and may be illegal. Unless otherwise stated, opinions expressed in this e-mail are those of the author and are not endorsed by the author's employer. _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Douglas Garstang
2006-Mar-17 00:04 UTC
[Asterisk-Users] Feedback from VON expo! Info on * HA andPolycomphone!!
Peter, Sorry, can't do inline replies with web based Outlook. Yes, I know... I'd say that if the phone wasn't available between the period the server went down, and the time it re-reregistered, then it's not a HA solution. I discussed with the people that make the decisions this evening, and having downtime like that is not an option. You'd also have no reliable BLF functionality as the subscribe and notify messages would be spread amongst multiple systems and just plain wouldn't work. Can you imagine what sort of traffic, say even 1000 phones re-registering every minute would be like? That's SEVENTEEN new registrations per second. Doug -----Original Message----- From: Peter Bowyer [mailto:peeebeee@gmail.com] Sent: Thu 3/16/2006 11:50 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Cc: Subject: Re: [Asterisk-Users] Feedback from VON expo! Info on * HA andPolycomphone!! On 17/03/06, Douglas Garstang <dgarstang@oneeighty.com> wrote: > David, > > How's DUNDi make this redundant? The way I understand it, a phone is only ever registered to a single Asterisk box at a time. If that Asterisk box where to fail, callers lose the ability to contact users that where registered on that box. Assuming you're using regcontext/regexten, if a phone isn't found locally then a DUNDi switch will allow it to be found elsewhere - assuming it has re-registered. It will only be unavailable during the re-registration interval. You need to go and try this, not keep posting about how you think it won't work. Then we can help you get it going. -- Peter Bowyer Email: peter@bowyer.org Tel: +44 1296 768003 VoIP: sip:peter@bowyer.org VoIP: *5048707000@sipbroker.com FWD: **275*5048707000 VoipTalk: **473*5048707000 _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/ms-tnef Size: 5894 bytes Desc: not available Url : http://lists.digium.com/pipermail/asterisk-users/attachments/20060317/19500376/attachment.bin
Douglas Garstang
2006-Mar-18 21:38 UTC
[Asterisk-Users] Feedback from VON expo! Info on * HA andPolycomphone!!
Huh? Phones do a NAPTR/SRV lookup in a specified domain to get a list of SRV records to use. The phones don't query the DNS server every time they make a call... they have a cache. You also run primary and a secondary (or two primary) dns servers. It's a simple scalable solution. It's a shame Asterisk doesn't support it. Doug. -----Original Message----- From: Aaron Daniel [mailto:amdtech@shsu.edu] Sent: Sat 3/18/2006 6:39 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Cc: Subject: Re: [Asterisk-Users] Feedback from VON expo! Info on * HA andPolycomphone!! Seems to me that it's more logical for the phones to know what their SRV records are than the server. You shouldn't rely on the dns to ensure that your system is redundant. Aaron On Mar 16, 2006, at 1:03 PM, Douglas Garstang wrote: > I know someone who's at VON this week. Apparently Mark Spencer was > up there talking about how Asterisk supports SRV. Sounds like > vaporware to me. > >> -----Original Message----- >> From: David Thomas [mailto:punknow@gmail.com] >> Sent: Thursday, March 16, 2006 11:54 AM >> To: Asterisk Users Mailing List - Non-Commercial Discussion >> Subject: Re: [Asterisk-Users] Feedback from VON expo! Info on * HA >> and >> Polycomphone!! >> >> >> In regards to HA... >> >> SER is definitely a good option, but it does require the extra >> hardware to have at least 2 boxes that can failover on each other. I >> would user OpenSER however (better documentation and mor features). >> >> I couldn't agree more that Asterisk should FULLY support DNS-SRV. The >> solution seems to work great for phones and ATA's. This would be a >> good item to create a bounty for. >> >> I have only two boxes right now, so it seems like my only HA options >> are the dreaded DUNDi setup or a active/passive failover with >> linux-HA. >> >> David >> _______________________________________________ >> --Bandwidth and Colocation provided by Easynews.com -- >> >> Asterisk-Users mailing list >> To UNSUBSCRIBE or update options visit: >> http://lists.digium.com/mailman/listinfo/asterisk-users >> > _______________________________________________ > --Bandwidth and Colocation provided by Easynews.com -- > > Asterisk-Users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
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