ATM (Asynchronous Transfer Mode) or PVC (Permanent Virtual Circuit)

(BSNL Circular No. 106-6/99 PHC dated 15.5.2002)

BSNL has set up ATM network with nodes at Delhi, Mumbai, Chennai, Kolkota and Bangalore. Initially Permanent Virtual Circuits (PVCs) will be offered on E1 and E3 ports. Even for sub E1 speeds the customer has to subscribe one E1 port. Similarly for intermediate speeds between E1 and E3, the subscriber has to take an E3 port.

During the experimental phase the following provisional tariff is offered for a period of one year :-
1. Registration fee  Rs. 1,000/- (non-refundable)
2. Security Deposit     Equal to one year’s port rentals (refundable but non-interest bearing).
3. Port rentals For E1 port Rs. 90,000/- per annum. For E3 port Rs. 3,46,000/- per annum.
Note :  Payable in advance, annually/quarterly
4. Period of Hire One year, However, if special constructions are involved the minimum period hire shall be three years.
5. Connectivity from ATM multiplexer to customer premises  Actual lease line charges as per the applicable tariff shall  be leviable.
6. Usage Charges The usage charges are based on the type of service selected  by the customer, the speed and the duration of usage. The tariff plan for service nrt–VBR (Non real time variable hit rate) is given below :

Table of Rates (Rs./Hour) for nrt-VBR Connections for National Traffic
Connection Speed(kbps) Total usage for various services per month (in Hours)
241-720 121-240 61-120 0-60
  Hrs. Hrs. Hrs. Hrs.
512 83 187 291 498
576 88 198 308 528
640 92 207 322 552
704 97 218 340 582
768 101 227 354 606
832 106 239 371 636
896 110 248 385 660
960 115 259 403 690
1024 119 268 417 714
1544 144 324 504 864
2048 170 383 595 1020

For other services the rates of nrt-VBR shall be multiplied with the factors given below. The services available on ATM and the corresponding factors are as under :
1. rt– VBR Factor – 1.1
2. CBR Factor – 1.2

Notes :
  • The charges in the table above are for bi-directional symmetric connections. The charges for unidirectional connections shall be 0.6 times of the bi-directional symmetric connection charges.
  • The charges for bi-directional asymmetric connection are sum of charge for each direction of the connection as per the calculation of unidirectional connection charges.
  • The charges above are for virtual channel connections. For virtual path connections the charges shall be 1.2 times.
  • The charges for intermediate speed like 4 mbps, 16 mbps and 34 mbps, the multiplication factor of 2, 4, 8, 11 respectively shall be applied to the rate applicable for 2048 kbps connection speed.
  • The charges in the table above are for P2P (Point to Point) connection.
  • Minimum duration for PVC (Permanent Virtual Circuit) usage is one hour. For a PVC having duration less than one hour and for fraction of an hour the charges for one hour connection would be applied
  • The usage per month shall be determined by totaling the usage by customer for various services, determining the category in which it falls and then applying the rates applicable to the usage (in hours) for various services used during the month.

7. Minimum Usage Charges A subscriber shall have to subscribe for minimum usage duration of 60 hours in a month.  In case lower usage, charges for minimum usage shall still be payable.
8. Miscellaneous Charges The charges for miscellaneous services such as change in bandwidth of PVC connections, change in VPI (Virtual Path  Index) values, activation/deactivation of PVC shall be a  fixed amount of Rs.3000 per request per item

9. At the time of applying for this services, the customer may intimate the size of the frame, maximum speed at which he desires to send (to define the PCR (Peak Cell Rate), average speed at which he desires to send (to define SCR (Sustained Cell Rate), to help the network administrator define the parameters such as CDVT (Cell Delay Variation Tolerance), MBS (Maximum Burst Size), etc. The customer may also inform the network administrator the category of service required.