Solved

Frame relay max data rate.

Posted on 2011-02-20
1,352 Views
I need to deterime the max data rate for a frame relay configuration, assuming no network congestion.  Please tell me the math as well.

map-class frame-relay TEST
frame-relay cir 256000
frame-relay bc 25600
frame-relay be 76800

PS - I understand that there are alot of assumptions regarding the surrounding network topolgy but please do not be concerned about that.  This is for a project and a good faith measurment based on only this snippet of configuration is fine.

0
Question by:agent2592
• 2
• 2

LVL 3

Expert Comment

ID: 34938811
frame-relay speed is going to be limited by two things.  The biggest is the physical connection itself.  If it's a full T1 then it's 1.54Mbs, if it's a fractional T1 the it would be whatever the sum of that channels is.  The second factor is the carrier CIR (committed information rate).  This is the speed the carrier is obligated to provide.  (the CIR can be less than the physical potential)  The speed can "burst" beyond the CIR (and often will), but the CIR is the contracted rate.

The snip you supplied would lead me to believe this is a fractional T1 with 4 channels associated with it.  This is represented by the 256000 (or 256Kbs) CIR rate.  It wouldn't make sense to have that statement in there is that wasn't the physical limitation of the circuit.
0

Author Comment

ID: 34938851
Consdering the Burst Commited and Burst Excess parameters, I know that the line will be allowed to burst beyond trhe CIR of 256Kbps.  That is what I am looking for.
0

Author Comment

ID: 34939368
I found the answer.  The "real" throughput is the bc.  This is the maximum allowable traffic within the tc window.  The be is the allowable amount of traffic beyond this, but it is discard eligible.  There for the maximum throughput it bc + be. Anything above this will be automatically discarded.

0

LVL 6

Accepted Solution

wpharaon earned 500 total points
ID: 34940467
The normal throughput is the Bc for each timeslot, the number of timeslots is calculated by dividing CIR to Bc "Committed Burst Size during an interval T", means 256000 / 25600, then you will have 10 timeslots. (your Tc is 100ms) 256000 bits will be transfered each second without being eligible to be discarded.
On top of that your Be (Excess Burst) which is eligible for being discarded if the Frame Relay network is congested.
Having that said we have 10 timeslots for each second, with Bc+Be = 102400, we multiply this by 10, then we have 1024000 bits per second on the condition of Frame Relay network running without any congestion
0

LVL 3

Expert Comment

ID: 34942458
I feel the answers given do provide value
0

Featured Post

AWS has developed and created its highly available global infrastructure allowing users to deploy and manage their estates all across the world through the use of the following geographical components   RegionsAvailability ZonesEdge Locations  Wh…
Network ports are the threads that hold network communication together. They are an essential part of networking that can be easily ignore or misunderstood, my goals is to show those who don't have a strong network foundation how network ports opera…
After creating this article (http://www.experts-exchange.com/articles/23699/Setup-Mikrotik-routers-with-OSPF.html), I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…