| Title: | atm |
| Moderator: | NPSS::WATERS |
| Created: | Mon Oct 05 1992 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 970 |
| Total number of notes: | 3630 |
Hi There , I wonder if someone can help me on this URGENTLY : I have got a question that was put to me by our customer. We have a number of PVC configured at the moment on the new DAGGL-BA ( QLC2s ) with CBR at 30 Mbps and s/w ver 2.1.1 at the moment ( CLIP ). The GS/ATM is between number of Cisco routers 7010( OC3s ). Our customer wants to implement LANE / SVCs next week. If they SHUT DOWN the PVCs on the Cisco router can the 30Mbps CBR bandwidth be used for the new SVC on the same link ????? Or do we need to remove that configured PVC on our GS/ATM to be able to use the full bandwidth on this link ???? My understanding that this was OK with the old DAGGL-AAs ( You did not need to remove the PVC. SVC could used the whole bandwidth on that link..... ). Many Thank in Advance . Youda Kopel , NPB Melb/Aust. [Posted by WWW Notes gateway]
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 945.1 | Re .0 CBR PVCs | KAMPUS::BRANDNER | That's noot eentiiirly aaacuuraate ... | Tue May 20 1997 05:33 | 30 |
>week. If they SHUT DOWN the PVCs on the Cisco router can the 30Mbps CBR >bandwidth be used for the new SVC on the same link ????? Or do we need to Yes. > Or do we need to >remove that configured PVC on our GS/ATM to be able to use the full bandwidth >on this link ???? No. If you configure CBR PVCs (i.e. 30 Mbps) it does *not* mean that those 30 Mbps are reserved and lost for other traffic. It does mean that the switch keeps resources reserved to do the *guaranteed* forwarding for the specified bandwidth. If the Ciscos don't send any cells for this CBR PVC this bandwidth is available for other connections (i.e. UBR SVCs). That's one of the main benefits of ATM over TDM (i.e. ISDN). Configuring CBR PVCs means to the switch: - if cells arrive on this PVC, *guarantee* forwarding for as much bandwidth as the PVC is configured for (i.e.30 Mbps). - if no cells arrive on this PVC (i.e. the PVC is shut down at the Cisco routers on both ends) use the bandwidth for other traffic. BTW: this also applies to CBR SVCs. Hope this helps. Rudi | |||||
| 945.2 | Need to confirm | NNTPD::"[email protected]" | Youda Kopel | Wed May 21 1997 01:38 | 20 |
Dear Rudi , Thank you for the reply. I just need to confirm this one before I pass it on to our customer ( VRN you may have heard ). Are you saying that I don't need to remove the configured PVCs on the GIGAswitch/ATM ?????? My customer is in the process of testing LANE / SVCs with GS/ATM and two Cisco 7000 routers. He want to ensure that if the LANE/SVCs don't work, he can fall back to the PVC configurations without " TOUCHING " the GS/ATM ... Please confirm this..... Many Thanks , Youda Kopel , NPB Aust. [Posted by WWW Notes gateway] | |||||
| 945.3 | Re .-1: confirmed | KAMPUS::BRANDNER | That's noot eentiiirly aaacuuraate ... | Wed May 21 1997 05:06 | 39 |
Youda,
>Are you saying that I don't need to remove the configured PVCs on the
>GIGAswitch/ATM ??????
Yep. That's what I say. There's still something to take care of. Be sure, that
the PVC's VCI you're using are above 64 (Signaling uses 5 and 16). VCIs in the
range of [0,63] are well known VCIs and therefore they shouldn't be used.
If your PVC's VCI range starts at, let's say 100 and is growing up, then there's
no problem at all.
Setting up SVCs the switch recognizes the configured PVCs and doesn't use the
PVC's VCIs.
>My customer is in the process of testing LANE / SVCs with GS/ATM and two Cisco
>7000 routers. He want to ensure that if the LANE/SVCs don't work, he can fall
>back to the PVC configurations without " TOUCHING " the GS/ATM ...
That's ok. But be sure that the Ciscos have the PVCs *disabled/removed* so they
don't send cells using the PVC's VCIs (which in turn means that the switch won't
receive cells on the PVCs).
You can check this by using the obm (2 -> 1 -> 8), i.e.:
InVCI: Type: Allocation: OutCard:Port:VCI: Xmit Cells: FLOWmaster
68 SVC ABR P-P ( 0 Mbps) 11: 2: 64 13662 On
72 SVC ABR P-P ( 0 Mbps) 11: 3: 64 15960 On
73 SVC ABR P-P ( 0 Mbps) 13: 4: 64 17338 On
74 SVC ABR P-P ( 0 Mbps) 11: 4: 64 12913 On
^^^^^^^^^^
If your customer is running LANE/SVC, the "Xmit Cells:" for the PVCs may NOT
increase.
Hope this helps.
Rudi
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