Best to Bridge or Route a multi-location system using T1 WAN and using UDP

[Anonymous]

I am deploying a new 2-way radio communications system that uses IP for its transport.  The Manufacture requires Multicast be enabled such that all sites can hear all others.

There are 7 locations in a star configuration total. One of the 7 is the Hub.  I have dedicated T1 connectivity from each of the remote sites to the Hub.

I have a 4305 at the hub, and 3200 units at each of the remote sites.

My original thought was to Bridge all the sites together creating a single network and thus enabling the multicast (UDP).

I have bridged between the 3200 units before, but not through the 4305.

At each site there is other equipment / devices that use TCP that also need to connect between sites.

I had selected a network of 192.168.122.xxx, but this is flexible at this point.

Any thoughts on the best way to configure this system.

[Anonymous]

:

Thank you for asking this question in the support community.  There are benefits for both bridging and routing in this application.  You mentioned that there are other pieces of equipment at each location, besides the two-way radios.  Do you know how many total devices there are at each location and how much traffic/bandwidth they are expected to utilize?  This may play a determining factor on if you design this network for bridging or routing. 

If you chose a bridged network, everything will be on the same broadcast domain; therefore, basic traffic will be sent/received across the WAN links, which could take up valuable network resources.  Routing would eliminate broadcast traffic on the WAN links, and depending on the number of hosts, may be more scalable, but would cause additional administrator configuration, as you would need to subnet each site, route statements, as well as configure multicast routing.

For future reference here is the Configuring Bridging in AOS document.  Also, if you configure routing, you will need to setup multicast routing.  Here is a Configuring Multicast Routing in AOS document.

Please, let me know if you have any questions about the differences about bridging versus routing.  I will be happy to help in any way I can.

Levi

[Anonymous]

:

I went ahead and flagged this post as “Assumed Answered.”  If any of the responses on this thread assisted you, please mark them as either Correct or Helpful answers with the applicable buttons.  This will make them visible and help other members of the community find solutions more easily.  If you still need assistance, I would be more than happy to continue working with you on this - just let me know in a reply.

Levi

[Anonymous]

Levi,

Sorry I didn't get back right away.  I did use the info you supplied and made some headway.

I was able to establish a point-point bridge using (2) 3200 units (one as line, the other as source)

Then I moved to connecting these units to the 4305 and attempted to bridge all 3 connections together.

At this point I have (2) of the 3200 units connected to the 4305 unit via T1 crossover connections.

I can get a IP bridge connection through a 3200 to the 4305 eth 2 port, but only one at a time works.

If I plug in both of the 3200 units, one gets a error, and won't bridge.

I have attached the current config files for review.

I'm not sure at what point the multiple T1 connections in the 4305 router have to be joined.

I am not trying to gain bandwidth using multiple T1's,  I need to bridge 6 remote locations to 1 main location. (all one big happy network)

Thank you for any thoughts.

Cliff

[Anonymous · Accepted solution]

:

Thank you for attaching the configurations.  I've noticed a few things that need to be changed on each location.

The remote location (NetVanta 3200):

1. The T1 1/1 is set for internal T1 timing; but I noticed the main side is also set for T1 internal timing.  I recommend leaving the main side as the clock source for the T1 (only one side can be internal) and setting the remotes to network timing (this is a default setting, but the command to configure it is clock source network).
2. There is no BVI configured.  You will need something similar to this:

interface bvi 1

  description BVI 1 bridge

  no ip address

  ip mtu 1500

  no shutdown

The main location (NetVanta 4305):

1. The issue with this location is in the PPP interface configuration.  The multilink command connects each of the T1s together into a single physical pipe.  Instead, you want single point-to-point T1s all on the same network in your application.  So, you will need multiple PPP interfaces.  Here is an example:

interface ppp 1

  bridge-group 1

  ppp mtu 1524

  no shutdown

  cross-connect 1 t1 3/1 1 ppp 1

!

interface ppp 2

  bridge-group 1

  ppp mtu 1524

  no shutdown

  cross-connect 1 t1 3/2 1 ppp 2

!

interface ppp 3

.

.

.

etc.

Please, make those modifications, and let me know if you have any additional questions.

Levi

[Anonymous]

Levi,

This worked !!!, So far I have 3 of the remote 3200 units all bridged to and through the 4305 unit.  I have some work to do to get the rest done, but it looks like I should be good.

One further thing.

The remote 3200 units I have only have (1) eth port, so in setting these up as bridges, I loose the ability to have a static IP address and GUI into the unit.

Does this apply to a telnet session also, or is there something I can do to at least have remote CLI sessions?

Thank you for all your help.

Cliff

[Anonymous]

Levi,

You can disregard the last concern about getting access to the GUI while in bridge mode.

I was able to accomplish this with a bvi section.

Thank you for your help

Cliff