Sig Perdomo
Depository Trust and Clearing Corporation


Biographical Sketch:
DEPOSITORY TRUST AND CLEARING CORPORATION – CRESTSIDE FACILITIES – Coppell, Tx Lead Network Systems Programmer / Engineer. • Given several presentations at SHARE - IBM International sponsored conference, on Mainframe Network Optimization & Tuning. Three recent ones have been under titles “A Tight Ship With Maximum Buoyancy”; “The Marriage of VTAM & TCPIP – VTAM Generics & SYSPLEX Distribution”, and most recent, “The Indigo Child Of SYSPLEX Distribution – Static To Dynamic”. • Further Enhanced Dynamic availability by changing Key Static VIPAs to Dynamic while maintaining the stacks identity thus causing Transparency to our external Clients while redoubling our availability, workload balance, reliability & scalability. Our entire Mainframe Enterprise is in such a mode now. • Developed new tools – REXX & SAS code, CONNTEST (Connectivity Tester), that replaced TELNET, SYSPLEX Integrity Checker. • Sheppard our Enterprise to be in “IP Application Centric Mode”. • Elected as a Project Officer in SHARE’s Network Management committee as related to Network Solutions and Directions. Have contributed to z/OS Communications Server enhancements. • Spear headed and coordinated with our 6 mainframe disciplines, an Initiative that Quadrupled our Availability while quartering MIP distribution in a 18 LPAR environment via enablement of SYSPLEX Distributor-TCPIP, Generic resources -VTAM, Session Manager, SME exits and VTAM generic RESOURCE exits to allow WLM to balance distribution. • OMPROUTE proof of concept tests – no loss of connectivity if recycled within a certain interval. – This represents another layer of availability. • Enabled OMPROUTE, routing daemon, into ARM policies via ARMWRAP. IBM added these tests into their Q&A environment. ARM is IBM’s Automatic Recovery Management component in Z/os. • Enabled Generic Resources in our NETPLEX customize Generic Resource exit ISTEXCGR. • Enabled ACB Modeling for CICS, MQ, DB2 to facilitate workload floating with minimal intervention and in DR scenarios. This was also part of our higher availability efforts thus avoiding ACB conflicts across a NETPLEX. • Wrote Standards and directions for the Network group as related to Enterprise Extender – client migration along with SNA/SNI and EE co-existence, Model ACBs, Dynamic VIPA, VIPARANGE, DDVIPA and their relation to each other, OBEY sub sections commands versus Profile OBEYs, DNS standards to facilitate at a glance, what the application is and where it normally resides. • Initiated Enterprise Extender with external clients. This has enabled us to decommission 4 of 8 - 3745’s, NCP and related license fees. This effort is ongoing. Part Enterprise Extender standards with clients is to be fully meshed across CEC’s. • Enabled IPL Order Relief for enhanced availability and the SYSPLEX Distributor. • Presentation of APPN/ HPR/ EE / SYSPLEX Distributor to Network and MVS systems programmers. • Migrated all Telnet servers from within the stack to Stand Alone TN3270 address spaces. • Migrated all Campus, Citrix, FTP, secure and not, and DB2 to SYSPLEX Distributed environment. • Fine Tune APPN and Enterprise Extender parameters to reduce overhead. • Wrote diagnosis procedures call ‘Inverted Pyramid Approach’ for APPN/ EE, which is a drill down methodology from Global symptoms to localized issues. • Install, migrate and maintain NETMATSTER – solve. • Enable Hyper sockets environment within our NETPLEX. • Enterprise Extender connect all VTAM LPARS and tune Network Node servers and End Nodes relative to CECs. • Enable and maintain all OSA and TRL definitions in VTAM and TCPIP via IUTSAMEH. • Introduced Global Virtual Routing Nodes with clients for performance gains in LU-LU sessions in and EE environment. • Perform various levels traces, diagnostics and debugging for TCPIP and VTAM. • IBM changed documentation as related to VTAM MODSRCH parm as a result of migration towards Generic resources and APPSTAT INQUIRE by Session managers. It basically did not work as stated. • Created and standardized our Default and Native adjacent cluster tables. This Enhances Searches for APPN EBN for qualified and non qualified network resources, as EBN’s cannot forward LOCATEs to Peer EBN’s. • Isolated an illusive Bug in APPN that had been around from VTAM V1R4 – V1R7. The Abstract was Adjacent Cluster Search Anomalies. After many traces, dumps and weekend tests an APAR was created and presented to me a SHARE 2006 by IBM. The APAR is OA15410. • Introduced in OMProute OSPF enhancements using wild card models for all current and future DVIPAs. • Identified overlapping Subnets and corrected via new methodology of wild card modeling in OMProute. • Headed Component recovery tests in which VTAM, TCPIP, OMPROUTE and NETVIEW were broken in various scenarios and documented recovery. • Support and maintained all VTAM, TCPIP and related network products on Mainframe. • Cross training initiated with CICSO 2811 routers, 7200 and 6513 Switch catalysts 7507 CIPS and Nokia Firewalls. • Support z/OS Comm server upgrades and related products from 1.5 through 1.7. • Review and exploit new enhancements in for SYSPLEX Distributor and Enterprise Extender in z/OS 1.7. • Identified Inconsistencies within APPC and MQ as it relates to ACB modeling. • Created a TCPIP Listener to present a Demo of DVIPA workings and inter-relations to network group. • Monitor and Tune CSM storage used by VTAM and TCPIP. • Tune APPN / EE and VTAM buffers to reduce trashing and overhead, such as TIBUF, T1 / T2 and CRPL pools. • Set up and maintain inventory of all Mainframe TCPIP addresses. • Extensive review of SMF 119 records for performance reporting. • Enabled SSL on NETPLEX for SYSPLEX Distributed sockets.