Throttling Bandwidth on 1601R

[trevorh13]

I have recently upgraded to a 1mb leased line but need to throttle it to 512k. (Sounds strange I know. Thing is the end node will only accept a max of 512K from us and 1mb was cheaper!)

I have issued the clockrate 500000 command on the s0 interface of both routers and also bandwidth 500 so my counters are accurate. Both routers are running as DTE devices.

The problem I have is that the link is still functioning at the full 1mb. The link is using HDLC encapsulation. Any ideas on what the problem is or can anyone sugggest an alternative method?

Many Thanks

Trevor (CCNA)

 

[ChrisAC]

You can't set the clockrate on DTE devices. DCE always sets the clockrate!

You have to remember that if your are running a leased line between remote sites, those sites are not directly connected. One site router will connect to a bearer at your ISP. This will function as the DCE setting the clock rate for that link. The other remote site will also terminate on the ISP's router and the traffic will be routed through the ISP's network between the two sites. The configuration of your on-site router needs to be matched with that of the ISP's router that your line terminates onto. If you want to reduce the bandwidth of your line, your provider will have to configure their equipment accordingly.

Chris.

 

[trevorh13]

This is an upgrade from the previous 256k Kilostream leased line. This had an external csu\dsu that sat between the router and the line to provide clocking. This has now been replaced with a Megastream NTU (Network Termination Unit) am I right in thinking then that this is what is now providing the clock signal?

Many thanks.

 

[ChrisAC]

Yeah .. that would provide the clocking signal (I think .. maybe someone could add to this??).

If you want to go down to 512K then speck to your service provider and have them make the necessary adjustments at their end.

Chris.

(I'll look into the CSU/DSU thing!!)

 

[ChrisAC]

Just as an afterpoint... the "bandwidth" command doesn't actually affect the bandwidth of the link. It's just used for weighting information for routing protocols!!

Just thought I'd mention it!!

Chris.

 

[trevorh13]

I was aware of that but thanks anyway. It looks as though I am going to have to go back to BT and get them to throttle it for me. I was loathed to do this as they charge £600 for the priviledge and a further £600 should I get the go ahead for a full 1 mb.

Never mind. Thanks for your help.