SRCF: Charging

How and Why Should SRCF Charge

The questions I would ask myself about the SRCF potentially reintroducing charges are as follows:

  • what are the overall goal of charging?
  • what conduct / resource usage should incur charges?
  • how will the charges be collected?
  • will there be any limiting principles on the charging / price structure?
  • does SRCF have the infrastructure to do this (in Membership Secretary and Sysadmin terms)?
  • what are the costs of charging?
  • what is charging supposed to achieve?
  • what will be the effects of charging?

Constitutionally, the SRCF may charge for membership of the Society, or for types of usage of the Facility. The Terms of Service impliedly assert that the Society may charge users for "excessive bandwidth use", though it is not clear that to do more than threaten this would be constitutional.

The SRCF has non-zero running costs. Meeting the SRCF's costs is one good reason for imposing charges. There is another: the manipulation of behaviour of the members in their rôle as users of the Facility.

Charging has bad side-effects, which should be taken into account when designing any system for doing it. Charges should be directed as closely as possible at whatever is causing the SRCF's costs. If the SRCF needs to meet a bandwidth cost, then charging for diskspace or CPU wastage is a bad idea, and unfair on anyone whose contribution to the costs is not in proportion to whatever they're actually being charged for. Cross-subsidising one expense from another is always going to cause distortions, and should be minimised.

The SRCF should charge no more than is necessary to finance the shortfall between expenditure and donations.


The main costs of the SRCF are hardware, bandwidth, electricity and administration. Hardware becomes (regarded as) obsolete very quickly these days, and loses its resale value so quickly as to be treatable more as a consumable than as a capital investment. CUSU foots the SRCF's bandwidth and electricity bills, though CUSU may not yet be aware that the cost of this has risen from being negligible to being a three figure sum annually. Revenues brought in by the SRCF can be put towards any of these expenses.

Activities the SRCF might want to curtail include, in the author's not very humble opinion, running unvetted CGI scripts. The sysadmins will generally have a list of their pet hate activities of the month, especially where resource contention is high (for CPU, RAM, diskspace or whatever).

Club goods: RAM, CPU and diskspace

The main resources the SRCF deals in are bandwidth, CPU, RAM and diskspace. The final three all function similarly: whereas only SRCF users can gain decent access to them, simultaneous use by more than an optimal number of users causes performance degradation. UNIX doesn't make it easy to enforce pre-emptive policies on such matters. The best one can do is generally monitor usage and correct user behaviour after the fact.

In the absence of resource contention issues, the best way of paying for RAM, CPU and disk is the existing system: you have to be a member of the SRCF club. Goods with these properties (easy to exclude non-contributors; performance degrades under crowding), such as movie theatres, are called "club goods" by economists. As it happens, it's possible to finance the acquisition of new hardware (the upstream provider of RAM, CPU and disk) through donations, and so the cost to the members of these goods falls to zero, which is exactly what happens at the moment. Only when there are serious resource contention problems should charging for RAM, CPU or disk be considered.

Network traffic

Bandwidth is a much bigger problem, since traffic is chargeable and not fully under the control of the SRCF's users. The SRCF needs to come clean to CUSU about how much its activities are costing CUSU. The costs and benefits of network traffic are diffuse: non-members of the SRCF, whether as consumers or providers of information on SRCF websites, benefit from the traffic to the SRCF's webserver. The direct providers of the websites are the easiest targets for charging for traffic. Accounting for traffic is going to be a nightmare.

The SRCF Committee must determine how much CUSU wants in payment for the traffic charges caused by the SRCF. It must be remembered that the SRCF hosts some CUSU websites, and nearly every single active member of the SRCF is also a member of CUSU, and the SRCF is widely regarded as a bloody good thing. It should also be noted that if push came to shove, the SRCF potentially has through its large membership base and large number of associated societies, groups, JCRs and so on, a very large lobbying base within the arithmetic of CUSU Council. Recourse should not be had to the Societies Syndicate, lest the politically healthy dependency of the SRCF on its members be lost.

With sufficient monitoring, and sufficient notice to users, multiple charging plans may be offered, along the lines of the mobile phone operators. It is to be hoped that the imposition of any charge for network traffic on an individual user only occurs in rare circumstances, and that the general cost of chargeable traffic can be met by donations.

Charging infrastructure

The SRCF has hundreds of active members. Charges could potentially mean a very large number of financial transactions. This would place a much greater burden on the SRCF administration than currently exists. Establishing and maintaining the infrastructure for dealing with the overhead of comprehensive charging is effectively equivalent to the effort required for a serious and sustained fundraising effort which would obviate the need for charging in the first place.

On a technical level, the SRCF lacks the recordkeeping (postprocessing of logs, mainly) to know what its current usage levels and trends are for CPU, RAM, disk, traffic and so on.

Managing members' expectations

Taking people's money will generate expectations as to levels of service. The SRCF must manage these expectations and meet them.


The SRCF used to charge money from users. Now it subsists on donations. Article 3 of the SRCF constitution, written by Matthew Vernon, the founding chairman, provides the SRCF with the potential for very flexible charging mechanisms: there can be annual membership charges, and charges for different types of use, the latter provision being the source of the flexibility.

Charges were found to discourage almost everyone from joining. Most potential users wouldn't have got value for money even at a fiver a year. When charging was abolished, membership increased massively and the whole ethos of the Society changed from being a club for techies to a club for everyone who wanted access to a useful computing environment.