Data Communications Networking Devices - 4th Ed.pdf

1.13 STANDARDS ORGANIZATIONS, ACTIVITIES AND THE OSI REFERENCE MODEL _____ 63other international bodies. BSI responsibilities include ensuring that Britishstandards are in technical agreement with relevant international standards,resultingin,as an example,the widespread use of the V.24/RS-232 physical interface inthe United Kingdom.CSAThe Canadian Standards Association CSA) is a private,non-pro®t organizationwhich produces standards and certi®es products for compliance with theirstandards. CSA functions similar to a combined US ANSI and UnderwritersLaboratory,the latter also a private organization which is well known for testingelectrical equipment ranging from ovens and toasters to modems and computers.In many instances,CSA standards are the same as international standards,withmany ISO and ITU standards adopted as CSA standards. In other instances,CSAstandards represent modi®ed international standards.International standards organizationsTwo important international standards organizations are the InternationalTelecommunications Union ITU) and the International Organization forStandardization ISO). The ITU can be considered as a governmental body asit functions under the auspices of an agency of the United Nations. Although theISO is a non-governmental agency,its work in the ®eld of data communications iswell recognized.ITUThe International Telecommunications Union ITU) is a specialized agency of theUnited Nations headquartered in Geneva,Switzerland. The ITU is tasked withdirect responsibility for developing data communications standards and consists of15 Study Groups,each tasked with a speci®c area of responsibility.The work of the ITU is performed on a four-year cycle which is known as astudy period. At the conclusion of each study period,a plenary session occurs.During the plenary session,the work of the ITU during the previous four years isreviewed,proposed recommendations are considered for adoption,and items to beinvestigated during the next four-year cycle are considered. The ITU's TenthPlenary Session met in 1992 and its 11th session occurred during 1996. Althoughapproval of recommended standards is not intended to be mandatory,ITUrecommendations have the effect of law in some Western European countries andmany of its recommendations have been adopted by both communications carriersand vendors in the United States.RecommendationsRecommendations promulgated by the ITU are designed to serve as a guide fortechnical,operating and tariff questions related to data and telecommunications.