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dotnet compact framework : Multicast and WM 2003
I'm having an issue getting multicast to work. I have created a simple
sender app and receiver app (separate apps). When I run the receiver app on the desktop and send from the pda, it works fine. When I send from the PDA to the desktop the packet never arrives. setup: The pda is connected to a lan with wifi and the desktop is connected via wired eth-net. The ap is connected to the same switch as the desktop. The pda is a dell axim running Windows mobile 2003. The desktop runs Win xp (sp1a). As the receiver, I can see igmp exclude requests from the pda when it joins the group. The ttl value is acceptable. I've tried both the udpclient class as well as writing the socket code myself, neither of which worked. I've tried different address and port combos. Does anyone have any clues on this one? Thanks! michael =)
[quoted text, click to view]
> When I run the receiver > app on the desktop and send from the pda, it works fine. When I send > from the PDA to the desktop the packet never arrives. I think these 2 statements talk about the same situation, so which scenario doesn't work? Do you have a firewall on a desktop? -- Alex Yakhnin, .NET CF MVP www.intelliprog.com | www.opennetcf.org [quoted text, click to view] "stu" wrote:
> I'm having an issue getting multicast to work. I have created a simple > sender app and receiver app (separate apps). When I run the receiver > app on the desktop and send from the pda, it works fine. When I send > from the PDA to the desktop the packet never arrives. > > setup: The pda is connected to a lan with wifi and the desktop is > connected via wired eth-net. The ap is connected to the same switch as > the desktop. The pda is a dell axim running Windows mobile 2003. The > desktop runs Win xp (sp1a). > > As the receiver, I can see igmp exclude requests from the pda when it > joins the group. The ttl value is acceptable. I've tried both the > udpclient class as well as writing the socket code myself, neither of > which worked. I've tried different address and port combos. > > Does anyone have any clues on this one? Thanks! > > michael =) >
Obviously, Alex's question needs to be answered, but you should also search
the archives, as Multicast has come up before, too. http://groups-beta.google.com/group/microsoft.public.dotnet.framework.compactframework?hl=en&lr=lang_en&ie=UTF-8&oe=UTF-8 Paul T. [quoted text, click to view] "stu" <stuboy@gmail.com> wrote in message news:1120144999.781331.250530@o13g2000cwo.googlegroups.com... > I'm having an issue getting multicast to work. I have created a simple > sender app and receiver app (separate apps). When I run the receiver > app on the desktop and send from the pda, it works fine. When I send > from the PDA to the desktop the packet never arrives. > > setup: The pda is connected to a lan with wifi and the desktop is > connected via wired eth-net. The ap is connected to the same switch as > the desktop. The pda is a dell axim running Windows mobile 2003. The > desktop runs Win xp (sp1a). > > As the receiver, I can see igmp exclude requests from the pda when it > joins the group. The ttl value is acceptable. I've tried both the > udpclient class as well as writing the socket code myself, neither of > which worked. I've tried different address and port combos. > > Does anyone have any clues on this one? Thanks! > > michael =) >
I did a quick search, but couldn't find anything; mostly what I saw was
stuff on the emu and multicast. Firewall, no my firewall is turned off. To clarify the other question pda send to pc = yes pc send to pda = no In general, I have a little more info. I got a hold of a pda with ppc 2002 and tried a couple things. I tried the same setup except used the ppc pda instead of the pc. I got the same result: ppc2k2 send to wm2k3 = no wm2k3 send to ppc2k2 = yes So, it looks like it is an issue with windows mobile 2003. Either that or I have completely pissed off WM 2k3 somehow. I'm going to see if I can get another WM 2k3 pda. Any thoughts on issues with WM 2k3? Thanks! michael =)
Just to clarify, I have Windows Mobile Second Edition.
A search on "multicast" gets 24 results...
You should check, since you're going through an AP on the wireless leg, that the AP isn't filtering that sort of message on the way out. If you have wired Ethernet capability on any of the PPC devices, you might try that, to eliminate wireless as the problem. In fact, one of the 24 results in this group indicates this as a likely explanation, so you should eliminate it before moving on to more aggressive measures. So, in *all* of these cases, *all* devices involved, whether sending or receiving, have joined the same multicast group, right? Successfully (you're checking return values of every socket method you call)? If you're convinced that your code is right, I'd next move to native code and do this straight through WinSock, which definitely does work with Windows CE 4.2-based devices. That takes another layer out of the equation. Paul T. [quoted text, click to view] "stu" <stuboy@gmail.com> wrote in message news:1120152934.495355.303540@g44g2000cwa.googlegroups.com... >I did a quick search, but couldn't find anything; mostly what I saw was > stuff on the emu and multicast. > > Firewall, no my firewall is turned off. To clarify the other question > pda send to pc = yes > pc send to pda = no > > In general, I have a little more info. I got a hold of a pda with ppc > 2002 and tried a couple things. I tried the same setup except used the > ppc pda instead of the pc. I got the same result: > ppc2k2 send to wm2k3 = no > wm2k3 send to ppc2k2 = yes > > So, it looks like it is an issue with windows mobile 2003. Either that > or I have completely pissed off WM 2k3 somehow. I'm going to see if I > can get another WM 2k3 pda. > > Any thoughts on issues with WM 2k3? Thanks! > > michael =) >
You're using IP addresses, aren't you?
Can you ping the device from a desktop? -- Alex Yakhnin, .NET CF MVP www.intelliprog.com | www.opennetcf.org [quoted text, click to view] "stu" wrote:
> I did a quick search, but couldn't find anything; mostly what I saw was > stuff on the emu and multicast. > > Firewall, no my firewall is turned off. To clarify the other question > pda send to pc = yes > pc send to pda = no > > In general, I have a little more info. I got a hold of a pda with ppc > 2002 and tried a couple things. I tried the same setup except used the > ppc pda instead of the pc. I got the same result: > ppc2k2 send to wm2k3 = no > wm2k3 send to ppc2k2 = yes > > So, it looks like it is an issue with windows mobile 2003. Either that > or I have completely pissed off WM 2k3 somehow. I'm going to see if I > can get another WM 2k3 pda. > > Any thoughts on issues with WM 2k3? Thanks! > > michael =) >
When I pulled in the 2nd PDA, they were both using wifi, on the same
AP. The sender doesn't have to be a part of the mutlicast group, but in this case it does join the group, because it is the only way to adjust the TTL of the packets being sent to the group. I have thought about going to native code, but would like to stay in .net land. I'm not doing anything unusual, so I would be interested as to why things aren't working. Yes, the devices can ping each other. I have been doing exception handling, but not paying much attention to the return values... I'll check those. michael =)
OK, and the sender should also receive the multicast, then. Do they?
I'm not saying that you should throw away the idea of actually implementing your program in .NETCF. I'm just saying that, in the process of debugging network problems, having anything layered on top of WinSock, whether it's ..NETCF, MFC, or whatever, more often then not hides the real source of problems. Since the problem seems to be "can't receive a multicast packet on a WM2003 device", dumping all of the stuff that might make you erroneously think that is a good idea before you just conclude that the OS is broken. Paul T. [quoted text, click to view] "stu" <stuboy@gmail.com> wrote in message news:1120156521.064072.137660@f14g2000cwb.googlegroups.com... > When I pulled in the 2nd PDA, they were both using wifi, on the same > AP. > > The sender doesn't have to be a part of the mutlicast group, but in > this case it does join the group, because it is the only way to adjust > the TTL of the packets being sent to the group. I have thought about > going to native code, but would like to stay in .net land. I'm not > doing anything unusual, so I would be interested as to why things > aren't working. > > Yes, the devices can ping each other. > > I have been doing exception handling, but not paying much attention to > the return values... I'll check those. > > michael =) >
This actually turned out to be a wifi issue. I'm in a building pretty
well painted by numerous APs and I was getting crazy packet loss on multicast packets. How about a round of applause for how 802.11 treats multicast. Anyway, I switched over to ad hoc mode and things worked much better.
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