June 2008 - Posts

• OCS AV edge call flow while remote

  WOW I had an epiphany today. I have attended a couple of presentations by Allen Shen formerly of Microsoft. And some presentations by Laura Chappell and both of them inspired me to really look at what is happening with Calls and Call control for OCS. Allen tried to explain ICE, STUN, and TURN to us in a presentation at Tech Ed. Which was really good but I still had some questions and still was not sure about it. If any of you attended this session or have seen one of allens sessions on ICE, STUN or TURN. then many of you realize it starts out very well but there is a point in the presentation where you become a little lost Generally this is when the lines start to cross. it is the same if you start to read the RFC's on those protocols as well. So I started last night trying to explain a little about the AV edge. And in the diagram it shows 2 users with voice traffic going through the AV edge server. Well I wanted to see more about this so I could confirm some things for myself. I began sniffing traffic (Thanks Laura Chappell you created a monster my wife can't understand why I am going nuts wanting to get home to see what the sniffs look like) to see what is actually happening. So here is a synopsis of what I found and how I found it. Let me explain what and how I tested this so far I will do more over the next couple of days. (it is so cool and so much fun to see how it all works) OK user A is at home behind a nat firewall with in internal IP of 192.168.33.74 the Router has a Public IP of 76.34.37.65 User B is on a wireless aircard from sprint. with an ip of 70.209.48.141  OCS AV edge server for the user A OCS environment is 74.88.32.5 User B is a a member of another federated company so they are not members of the same company or the same OCS systems. User B is calling user A User B right clicks on the users and says make communicator call to user A.   user B begins sending sip traffic to his OCS server. I am not going to go through all this but ultimately the 2 access edges pass sip call control traffic back and fourth to each other at some point USER A sends back a list of possible IP's that user B may be able to contact him at. here is the list. a=candidate:ji0XDiGUsQde1Fr4OZC9yqAwEIZBMAUavSjGXQkOfos 1 YPqc4I+bY14FUpKJh2Rtlg UDP 0.830 192.168.33.74 25856 a=candidate:ji0XDiGUsQde1Fr4OZC9yqAwEIZBMAUavSjGXQkOfos 2 YPqc4I+bY14FUpKJh2Rtlg UDP 0.830 192.168.33.74 56576 a=candidate:LRJGqNyquostNMw5jcDIBsW31GtYQ/cYw8fY2cWZ/Ek 1 V8p3r9V8NrclMS0ZNshlbA TCP 0.190 74.88.32.5 59722 a=candidate:LRJGqNyquostNMw5jcDIBsW31GtYQ/cYw8fY2cWZ/Ek 2 V8p3r9V8NrclMS0ZNshlbA TCP 0.190 74.88.32.5 59722 a=candidate:iIp3PUfo9f8PUICapk9cbvNixh3G//E0YcN/H1BS2uU 1 gJOKyEAWqEO3fRvwo7zibw UDP 0.490 74.88.32.5 52410 a=candidate:iIp3PUfo9f8PUICapk9cbvNixh3G//E0YcN/H1BS2uU 2 gJOKyEAWqEO3fRvwo7zibw UDP 0.490 74.88.32.5 55690 a=candidate:SwYcgzmLKxjngz0ly88fx3WyBfeLJyFpUSooOFbqiCw 1 AVJa9tLvi/OL7UAMrXtiQg TCP 0.250 76.34.37.65 64896 a=candidate:SwYcgzmLKxjngz0ly88fx3WyBfeLJyFpUSooOFbqiCw 2 AVJa9tLvi/OL7UAMrXtiQg TCP 0.250 76.34.37.65 64896 a=candidate:Kg7LyhMXrFauBM795AMdGHe12oSjdFMnYjThzovUlLY 1 T0uIkUWv0qOZXsAjK9NgDg UDP 0.550 76.34.37.65 4864 a=candidate:Kg7LyhMXrFauBM795AMdGHe12oSjdFMnYjThzovUlLY 2 T0uIkUWv0qOZXsAjK9NgDg UDP 0.550 76.34.37.65 27520 They are called A=Candidates notice there are 10 listed. these sometimes may be referred to as Candidate pairs. notice there are TCP and UDP pairs. once this is passed back to USER B then stun negation begins to take place. and ultimately different patterns are tried until it is finally determined which path is best  to take. in this case User B was able to talk directly to USER A via UDP. So the sniff ultimately showed 192.168.33.74 talking directly to 70.209.48.141. Because there are so many variables it is hard to say what the voice path is for each and every call. So if someone asks "What is the RTP traffic flow in OCS" the only answer that is possible is it depends. From what I understand so far I believe it is possible for voice traffic to be peer to peer in a multitude of situations. I will start a trace on a 3 person conference call via MOC next. but that may be a day or 2.   Thanks. hope this helps someone. Posted Jun 20 2008, 07:17 PM by mitchroberson with no comments

• OCS Edge server deployment (understanding a multi-homed network card setup for the access edge)

  So you want to set up OCS to work remotely. you read the documentation and try to decide how you want to deploy the edge servers so you can have remote access. There appears to be  a lot of confusion about what is needed and how it all works. so let me see if I can explain a little better. in a small deployment that wants voice video, live meeting, IM presence to have remote access.  here is what you need and what it does. consolidated edge (this has the Access Edge, Web Conferencing Edge, and A. V edge installed on the same box) ISA Server for Address book download, Group Expansion while remote, and Live meeting Content Download. Access Edge, Web conferencing edge, AV edge, all consolidated on the same box. So you can have all 3 roles loaded on the same box but that brings some challenges that we will discuss shortly. So what does each server and server role do at the edge. Now remember I am not trying to be extremely technical and my description may be a little off but the general traffic flow is correct and the general use of  each server is correct Access edge proxy's Call Control traffic back to the OCS Front end servers. it also proxies IM and presence traffic from remote users. So When a user is remote or federated all im and presence.nse traffic proxy's through the access edge no other server is involved in the DMZ. Web conferencing Edge server is a proxy for live meeting traffic to the conferencing focus which is on the OCS front end server in most cases. However the initial setup of the live meeting session is initiated through the access edge. during the initial setup of the conference information is passed about the web URI for the live meeting server to the client so it can find the web conferencing edge server. during this same session initiation the web url to the ISA server for content download is passed to the client as well. AV edge role is used for Voice and Video proxy so that a user that calls a remote user from inside will initiate the call. which will take advantage of the access edge to establish call control. from this, call control information is passed that tells both clients (the one inside the LAN and the one remote) to send all audio and video traffic through the AV edge. So what this means is all clients in the LAN need to be able to send traffic to the AV edge.  an interesting note is that when a call is initiated internally then the call is peer to peer for the voice and video. When it is remote the video and voice must hit the AV edge. Also when a conference call is established a different path is followed. in a conference call all Audio, video is sent to the front end server so it can be mixed and sent back out. ISA server used to proxy the location of he Address book download files, Group expansion files, and finally live meeting content. So will live meeting work with out this in place and will MOC work with out it. Yes it will however for MOC you will not recieve new address book downloads while being remote. And Group expansion may have some problems but the client still works. As far as live meeting this depends on what functionality you need. this is where any uploaded files would be located so if you want to upload PowerPoints for presentations then this is needed. also if you want to post handouts then it is also a needed resource. Some people suggest just opening up port 443 direct to the front end server but this is not supported not recommended and VERY Risky. The diagram below shows the three roles on separate servers for simplicity I have left the ISA server out for the time being this will be discussed later. and this is only showing a remote user to internal user. I know my picture is not great. but hey I never claimed to be an artist or even a master at Visio.     Posted Jun 19 2008, 08:41 PM by mitchroberson with no comments

• Conducting Meetings with Technology

  So you finally have live meeting up and running and you start to tell everyone it is working and available. The boss takes you up on using it for a meeting and comes back saying this sucks. Now you begin to wonder if it is all it is cracked up to be. What do you do? Since I work with live meeting all the time there are some things I have noticed that may make conducting a live meeting more successful. Live meeting is not the same as having all the users in the same room.Nor is a confernce phone the same as having everyone in the same room. So why do people continue to treat it the same. this is just not possible have you ever been on a conference call when you are the remote caller and there are 10 other people in a meeting room with one of those cool polycom phones. And multiple conversations start up in the room YOU HAVE NO IDEA HOW ANNOYING THIS is it is a complete waste of time. you can not tell who is talking and what is important. Live meeting is no different. so here are some ground rules to conducting meetings using technology this is not just about live meeting but the examples will use live meeting. Set ground rules only one person talks at a time No pen tapping No dragging your computer across the table (this is an ear killer) No typing (set your computer in your lap and tap the keys lightly Set 2 people up as the presenter. In case the real presenter is remote and loses connectivity. the other can quickly take over Set a person up to help the remote users. have them watch the icons to see if status changes. pre stage documentation Setup the live meeting before hand have handouts ready make sure presentation is uploaded. Shareing your desktop powerpoint is a process killer. Play with it before the first meeting If video does not work well move on. Mute everyone but he speaker initially if you are a remote user mute your mic before you join. These are just some of the guidelines I like to use. I will post more as time permits.  Posted Jun 19 2008, 08:03 PM by mitchroberson with no comments

• Vista Slow or Unresponsive (outlook 2007 unresponsive)

  All I have been fighting a battle with vista that has been killing me and many others. There are tons of posts about this issue but i think I have found it and it is an age long problem that has been around for years but we often forget about it. How many of you have had the infamous I am typeing and it takes a while for the screen to catch up. or outlook hanging and saying "not responding" it seems now that I have found my problems. I was at a point that vista was almost unusable but I kept digging at it. and here is what I found.   First Turn off Aero it  seems to improve things considerably. I did find going to classic view helped a ton. But I still had problems with outlook and other things. Second I went into Anti-virus and excluded scans on ost's, pst's, and I excluded the outlook.exe  executable.   I restarted my machine and what a surprise I have been functioning back at windows XP levels of speed again it is awesome.  Posted Jun 02 2008, 07:55 PM by mitchroberson with 1 comment(s)