Overview - ISO/IEC 10030:1995 (End System Routeing Information Exchange Protocol)
ISO/IEC 10030:1995 defines the End System Routeing Information Exchange Protocol (for use with ISO/IEC 8878) to exchange routing information between End Systems (ES), Intermediate Systems (IS) and a Subnetwork Address Resolution Entity (SNARE). This second edition (1995) replaces the 1990 edition and is specifically targeted at environments using X.25/ISO‑IEC 8208 to provide the OSI connection‑mode Network Service. The standard addresses Single Subnetwork Routeing and complements other OSI routing frameworks (see ISO/IEC TR 9575).
Key topics and technical requirements
- Scope and applicability
- Applicable to ES, IS and SNAREs operating with ISO/IEC 8878 and ISO/IEC 8208 (X.25/PLP).
- Excludes terminal equipment using certain fast select procedures (see standard).
- Protocol subsets
- Configuration Information subset - allows ES/IS to notify a SNARE of reachable Network Addresses (NAs) and to learn SNPA addresses and temporary NET assignments.
- Redirection Information subset - enables redirection of connection attempts to appropriate SNPA addresses when direct addressing is insufficient.
- Assumptions and design goals
- Assumes subnetwork can route to SNPA on same subnetwork but not globally using NSAP alone.
- Designed to minimize a priori state, reduce memory for routing tables, and lower routing algorithm complexity in End Systems.
- Protocol data units (PDUs) and procedures
- Defines PDUs such as ECQ, ENC, ERA, ESC, ESH, RD, SAA, SCC, SCR, SHL, SNC, SRH, SRN and procedures for SNARE interaction, address assignment, notification and redirection.
- Conformance and testing
- References Protocol Implementation Conformance Statement (PICS) and conformance methodology (ISO/IEC 9646).
Practical applications and who uses it
- Implementers of legacy OSI/X.25 networks who need single‑subnetwork routing and address resolution.
- Vendors building or maintaining SNARE services, End Systems or Intermediate Systems that interoperate with ISO/IEC 8878 and ISO/IEC 8208.
- Network architects and telecom engineers working on interoperability, address assignment (NET/SNPA), and redirection in X.25-based subnetworks.
- Organizations preserving or migrating legacy telecommunications systems where OSI addressing and routeing exchanges remain required.
Related standards
- ISO/IEC 8878 (Use of X.25 to provide OSI connection‑mode Network Service)
- ISO/IEC 8208 (X.25 Packet Layer Protocol)
- ISO/IEC 9542 (End system to Intermediate system routeing exchange) - complementary but not fully applicable to X.25/PLP environments
- ISO/IEC 8348, ISO/IEC 8648, ISO/IEC TR 9575, ISO/IEC 9646 (conformance)
Keywords: ISO/IEC 10030, End System Routeing Information Exchange Protocol, SNARE, ISO/IEC 8878, X.25, ISO/IEC 8208, SNPA, NSAP, Network Address, routeing, single subnetwork routeing.