MTU Size when connecting an RMX Bridge to endpoints on MPLS network seem to create massive packet loss that kills the multi-point active Multi-Point call.

This is from Microsoft:-

If you receive Server Error: 0x80048849 and/ or 0x80048820 in Windows Live Mail at home or while you're in your regular network, it may be due to the setting of the MTU (Maximum Transmission Unit) on the mail client.
If you get this synchronization error at a coffee shop, airport or a place from where you don't usually connect to the internet, we suggest synchronizing mail on your regular internet connection.
When the MTU setting on the mail client is larger than the MTU settings configured on network devices between your mail client and the mail client servers, some data packets may be lost, causing mail synchronization to fail.
Follow the steps given below to fix synchronization errors due to mismatched MTU settings:
Determine the MTU setting on your network device
Apply the MTU setting to your mail client
Determine the MTU setting on your network device
This is a trial and error process, and will be different for each user. You may have to repeat the procedure below a few times, before you can find out the MTU setting of your network device. Follow the steps below:
Open command prompt
Click Start ? Run ? Type cmd
In the Command Prompt Window, type in the following:
Ping <Mail server address> -f -l 1500
Notes:
The <Mail server address> is the IP address of the mail server that you are unable to synchronize with.
For Hotmail, 65.55.33.106 is the IP address for DeltaSync (mail.services.live.com).In this document we will be using this IP address as an example.
In the -l 1500, 1500 is the max MTU for Ethernet connections.
You may get an error like this (100% packet loss):
C:\Users\username>ping 65.55.33.106 -f -l 1500
Pinging 65.55.33.106 with 1500 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 65.55.33.106:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss)
If you received the error above, subtract 28 from the 1500 bytes of data. In the Command Prompt Window, type in the following:
Ping <Mail server address> -f -l 1472
If you get a 0% Packet Loss with 1472, it means the MTU setting of your configured network is 1472
Note: If you continue to receive the error described in (b) above, repeat the above steps by subtracting 28 from 1472 bytes of data. Repeat these steps until you get a message for 0% packet loss. If you were able to communicate with the mail server at an MTU size of 1424, you will receive the following:
C:\Users\username>ping 65.55.33.106 -f -l 1424
Pinging 65.55.33.106 with 1424 bytes of data:
Reply from 65.55.33.106: bytes=1424 time=230ms TTL=241
Reply from 65.55.33.106: bytes=1424 time=196ms TTL=241
Reply from 65.55.33.106: bytes=1424 time=162ms TTL=241
Reply from 65.55.33.106: bytes=1424 time=163ms TTL=241
Ping statistics for 65.55.33.106:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss)
Approximate round trip times in milli-seconds:
Minimum = 162ms, Maximum = 230ms, Average = 187ms
Apply the MTU setting to your mail client
Follow the steps below:
Open command prompt as administrator (you must be an admin on the computer)
Click Start ? Run ? Type cmd
In the Command Prompt Window, type in the following:
netsh int ip show int
You will receive a message similar to the following. Find the connection name that you use to connect to the internet and note the Idx value
C:\Users\Username>netsh int ip show int
Idx Met MTU State Name
--- ---------- ---------- ------------ ---------------------------
1 50 1472 connected Loopback Pseudo-Interface 1
11 20 1472 connected Local Area Connection
To apply the correct MTU setting on your mail client, type the following in command prompt:
netsh int ip set interface <Idx value> mtu= <MTU setting of your router> store=persistent
Press Enter
For example, if the correct MTU setting was 1424 and Idx value of your connection was 11, you will type:
netsh int ip set interface 11 mtu=1424 store=persistent
If (c ) was successful, you will receive the confirmation message "Ok"
Exit command prompt
Restart your computer
Open WL Mail and see if the issue persists.
have Windows Vista Home Premium Recently unable to send or recieve Window...

Packet data (EGPRS) Enhanced general packet radio service (EGPRS), packet data, is a network service ceive data over an Internet protocol which allows mobile phones to send and re (IP)-based network. It enables wireless access to data networks such as the Internet.77 . 2005 Nokia. All rights reserved © Copyright The applications that may use packet data are MMS, browsing sessions, Push to talk, e-mail, remote SyncML, Java application downloading, and the PC dial-up. Packet > Connectivity > Settings > Menu To define how to use the service, select Packet data connection > data . to set the packet data connection to be established when an When needed Select application needs it. The connection will be closed when the application is terminated. to set the phone to automatically connect to an packet data Always online Select network when it is switched on. indicates a packet data connection. Modem settings You can connect the phone using an IR or a data cable connection to a compatible PC, and use the phone as a modem to enable packet data connectivity from the PC. > Settings > Menu To define the settings for connections from the PC, select , activate Active access point > Packet data settings > Packet data > Connectivity Alias . Select Edit active access point the access point you want to use, and select , and enter a nick name for the currently selected access point. for access point , and enter the access point name (APN) to Packet data access point Select establish a connection to an EGPRS network. You can also set the dial-up service settings (access point name) on your PC using If you have set the 121 p. PC Suite the Nokia Modem Options software. See . settings both on the PC and on your phone, the PC settings are used.

make sure that you have the right access point.
depending on your network, your phone may use different access points for multi-media messaging, streaming, and web browsing.

you can manually input these access points in
Settings>>Connection Settings
or
Settings>>Phone Settings >>Connection Settings

and look for Data Packets, or Access points.

or you can have your network provider send you the configurations by providing them your unit model by calling their hotline. Most network providers should have this service for free.

[NB3600]---fr_uni---(PE1)----FE----(PE2)---fr_uni---[NB3600]----[NB NMS]

below is the config.

> *PE1*
> fe-0/0/0
> description "conctd to PE2";
> mtu 1546;
> unit 0 {
> family inet {
> address 192.168.0.1/30;}
> family mpls;}
>
> e1-1/0/0
> description "conctd to NB3600";
> encapsulation frame-relay-ccc;
> lmi {
> lmi-type ansi;}
> unit 0 {
> encapsulation frame-relay-ccc;
> point-to-point;
> dlci 513;
> family ccc;}
>
> l2circuit
> neighbor 192.168.1.254
> interface e1-1/0/0.0 {
> virtual-circuit-id 513}}
>
> *PE2*
> fe-0/0/0
> description "conctd to PE1";
> mtu 1546;
> unit 0 {
> family inet {
> address 192.168.0.2/30;}
> family mpls;}
>
> e1-1/0/0
> description "conctd to NB3600";
> encapsulation frame-relay-ccc;
> lmi {
> lmi-type ansi;}
> unit 0 {
> encapsulation frame-relay-ccc;
> point-to-point;
> dlci 513;
> family ccc;}
> l2circuit
> neighbor 192.168.0.254 {
> interface e1-1/0/0.0 {
> virtual-circuit-id 513;
> }}

You are trying to establish a point-to-point link between two buildings. You need one access point and one bridge. Technically, it doesn't matter which one you put at which end. Traditionally, you put the AP where the network connection is, because it makes adding future remote locations easier.
500 yards should be a cakewalk for this model.

In computer networking, the term Maximum Transmission Unit (MTU) refers to the size (in bytes) of the largest packet that a given layer of a communications protocol can pass onwards.
MTU parameters usually appear in association with a communications interface (NIC, serial port, etc.).
The MTU may be fixed by standards (as is the case with Ethernet) or decided at connect time (as is usually the case with point-to-point serial links).
A higher MTU brings higher bandwidth efficiency. However, large packets can block a slow interface for some time, increasing the lag on other packets. For example, a 1,500-byte packet, the largest allowed by Ethernet (and most of the Internet), would block up a 14.4k modem for about one second.
The default MTU on a PPPoE connection is 1,492. The default MTU for a DHCP or PPPoA connection is 1,500.
Increasing the MTU size beyond these levels is possible on a client computer, but not recommended, because the MTU size on the outbound connection to the ISP will nullify any potential gains from a larger MTU.

MTU Means Maximum transmission unit In computer networking, the term Maximum Transmission Unit (MTU) refers to the size (in bytes) of the largest packet that a given layer of a communications protocol can pass onwards. MTU parameters usually appear in association with a communications interface (NIC, serial port, etc.). The MTU may be fixed by standards (as is the case with Ethernet) or decided at connect time (as is usually the case with point-to-point serial links). A higher MTU brings higher bandwidth efficiency. However, large packets can block up a slow interface for some time, increasing the lag for further packets. For example, a 1500 byte packet, the largest allowed by Ethernet at the network layer (and hence most of the Internet), would tie up a 14.4k modem for about one second

I personally have never known that changing the MTU setting can speed up your connection, as the MTU is the maximum transmition units that is sent to your pc from each web site and if the MTU setting is incorrect then some web sites will not load on your explorer page, the speed at which you download the page will not make any difference.

If you are supposed to get 20MB speed then you must be on cable and not ADSL as ADSL is a max of 8MB, so i would ring up Virgin or whoever and check the speed you should really be getting.

See these details posted on the netgear site, and you'll notice there is no mention of speed:-

Details About MTU
A packet sent to a device larger than its MTU is broken into pieces. Ideally, MTU would be set to the same — large — value on all your computers, routers and switches, as well as on all the parts of the Internet that you access. But you cannot control the MTU on the Internet, and in practice the optimum MTU size on your LAN is related to your hardware, software, wireless interference, etc.

• Tweaking MTU size may work well in one situation, but cause performance and connection problems in others.
• When network devices with different MTU settings communicate, packets are fragmented to accommodate the one with the smallest MTU.
• Windows XP sets MTU automatically, that is, it optimizes computer MTU for you. This Microsoft article explains resolving lack of connection to a broadband ISP using Windows XP: How-To Configure Broadband Connections Using PPPoE.
• Once a network device fragments a packet, the data stays fragmented until arriving at the destination computer.

Setting MTU size is a process of trial-and-error: start with the maximum value of 1500, then reduce the size until the problem goes away. Using one of these values is likely to solve problems caused by MTU size:

• 1500. The largest Ethernet packet size; it is also the default value. This is the typical setting for non-PPPoE, non-VPN connections. The default value for NETGEAR routers, adapters and switches.
• 1492. The size PPPoE prefers.
• 1472. Maximum size to use for pinging. (Bigger packets are fragmented.)
• 1468. The size DHCP prefers.
• 1460. Usable by AOL if you don't have large email attachments, etc.
• 1430. The size VPN and PPTP prefer.
• 1400. Maximum size for AOL DSL.
• 576. Typical value to connect to dial-up ISPs.

MTU, Partial Loss of Internet Connection, and Performance MTU (Maximum Transmission Unit) is the largest packet a network device transmits. The best MTU setting for NETGEAR equipment is often just the default value. MTU is sometimes presented as something that can be easily changed to improve performance, but in practice this may cause problems. Leave MTU unchanged unless one of these situations applies: 1. You have problems connecting to your ISP or other Internet service, and their technical support (or NETGEAR's) recommends changing MTU. For example, these services may require an MTU change: * Yahoo email * MSN * AOL's DSL service 2. You use VPN, and have severe performance problems. 3. You used a program to "optimize" MTU for performance reasons, and now you have connectivity or performance problems. * An easy solution to most problems is to change MTU to 1400. * If you are willing to experiment, gradually reduce MTU as described in "Details of MTU", below. How to Change a Computer's MTU Size Note: If you change MTU on one computer, it is likely you will want to change it on your other computers, switches, and routers, as well. Instructions for changing MTU on other NETGEAR devices is found in the Reference Manuals. The third party Dr. TCP software can be used to change the MTU setting. 1. Download it from this link, choosing the zip file or the exe file at the top of the page. 2. Run the utility. 3. In the Adapter Settings pull down, select the Ethernet driver and adapter used to connect with the network. 4. In the MTU box, type the MTU size you are trying. 5. Click in any other box, without changing the data there. 6. Click Save. 7. Click Exit. 8. Restart the computer. Details About MTU A packet sent to a device larger than its MTU is broken into pieces. Ideally, MTU would be set to the same ? large ? value on all your computers, routers and switches, as well as on all the parts of the Internet that you access. But you cannot control the MTU on the Internet, and in practice the optimum MTU size on your LAN is related to your hardware, software, wireless interference, etc. * Tweaking MTU size may work well in one situation, but cause performance and connection problems in others. * When network devices with different MTU settings communicate, packets are fragmented to accommodate the one with the smallest MTU. * Windows XP sets MTU automatically, that is, it optimizes computer MTU for you. This Microsoft article explains resolving lack of connection to a broadband ISP using Windows XP: http://www.microsoft.com/windowsxp/using/networking/learnmore/ppoe.mspx * Once a network device fragments a packet, the data stays fragmented until arriving at the destination computer. Setting MTU size is a process of trial-and-error: start with the maximum value of 1500, then reduce the size until the problem goes away. Using one of these values is likely to solve problems caused by MTU size: * 1500. The largest Ethernet packet size; it is also the default value. This is the typical setting for non-PPPoE, non-VPN connections. The default value for NETGEAR routers, adapters and switches. * 1492. The size PPPoE prefers. * 1472. Maximum size to use for pinging. (Bigger packets are fragmented.) * 1468. The size DHCP prefers. * 1460. Usable by AOL if you don't have large email attachments, etc. * 1430. The size VPN and PPTP prefer. * 1400. Maximum size for AOL DSL. * 576. Typical value to connect to dial-up ISPs.