I found these examples regarding "telephone conference", but there might be different reasons for vringo's conference call:
With the exception of scheduled telephonic conferences, and as provided at section V.B below, telephone calls to chambers are permitted only for matters such as scheduling and calendaring. Court personnel are prohibited from giving legal
advice or discussing the merits of a case.
Following telephonic contact with chambers, counsel will be required to file an ex parte or Joint Motion, as appropriate, which will be granted only upon good cause shown.
D. Telephone Conferences
Judge Robreno may hold telephone conferences to resolve scheduling matters or discovery disputes. Counsel will be notified of the date and time for the telephone conference. It will be the responsibility of counsel for the moving party to initiate the telephone conference and to contact Judge Robreno through his secretary after all parties are present on the call.
Once a motion to compel is filed, Judge Robreno will schedule a telephone or in-person conference to resolve the dispute within ten (10) days. [...] Judge Robreno permits telephone conferences to resolve discovery disputes during depositions in cases where the deposition would otherwise have to be adjourned.
Judge Robreno generally will hold a telephone scheduling conference with counsel in criminal cases shortly after arraignment. At the conclusion of the conference, Judge Robreno will issue a Scheduling Order governing speedy trial issues, discovery, time for filing motions, and the trial date.
Judge Padova sometimes uses telephone conferences for non-complex pretrial conferences, scheduling, discovery disputes, settlement conferences and other like matters. Telephone conferences should be arranged through the Deputy. Judge Padova expects counsel to bring matters to his attention only after they have been discussed with opposing counsel. All parties must be represented on any telephone conference with Judge Padova. Counsel have the responsibility to initiate telephone conferences and to contact Judge Padova through his Deputy after all other parties are present on the call.